DE102006000820A1 - Method for producing analog vertical-deflection signal for vertical deflection of electron beam in picture tube with digital vertical-deflection signal, involves signal path and return section - Google Patents

Abstract

Method involves signal path and return section (r). The return section runs from a height of the measuring area (m) up to the height (h) as a return height within the represented picture area (B) and after a time duration (b) runs in reverse manner except for the height of the edges of the represented picture area. An independent claim is also included for the integrated circuit.

Description

The The invention relates to a method for generating an analog Vertical deflection signal with the preamble features of the claim 1 or to an integrated circuit for carrying out such a method.

For a vertical deflection of an electron beam in picture tubes becomes a sawtooth-like Signal generated. This starts in an upper overscan area (oversampling area) and runs while a picture or field to the lower Overscannbereich. After that there is a fast return to upper overscan area. When displaying an image in the format 16: 9 on a picture tube for pictures in the 4: 3 format, the distraction is no longer in the overscan areas but only until the beginning or the end of the 16: 9 picture, which has a smaller vertical amplitude than the 4: 3 image.

To the Generating the vertical deflection signal are integrated circuits (IC: Integrated Circuit). These integrated circuits have two special features. First, after the vertical returns The distraction should always be in the upper Overscanbereich, as there measuring lines for a balance of cutoff and for White Drive (white balance control) for the picture tube are located. These measuring lines are allowed not be visible and must lie above a picture border. Second, in many applications digital / analog converters in the form of PWM converters (PWM: Pulse Width Modulation) with current outputs which consists of a digital vertical deflection signal of integrated circuit produce an analog vertical deflection signal. When using such digital / analog converter, the signals must be low-pass filtered to get an analog signal.

Generally should the return the deflection signal as possible done quickly. The required speed for the return is but slowed by the low pass. To fix this problem, are so-called return booster installed in circuits. Return Booster are additional transistors, which quickly reload the low-pass capacitors of a low-pass circuit. By Such an arrangement is the return in 4: 3 images for Display on a 4: 3 monitor no problem.

at the appearance of 16: 9 images on a 4: 3 picture tube arise However, problems because of the return must be in the upper Overscanbereich to the measuring lines. From the upper overscan area, the deflection signal must be at the end the measuring lines as possible come quickly to the beginning of the 16: 9 picture, which is typically has an area not described above and below, so the aspect ratio is displayed correctly. For this However, there is no booster available in the area of the deflection signal could speed up the distraction. This will stretch the spacing of the first lines of the 16: 9 image, and the more stretched, the larger the screening capacities are.

The The object of the invention is an improved method for proposing an analog vertical deflection signal, which in particular the Rücklaufproblematik when displaying 16: 9 pictures on a 4: 3 picture tube or at least reduced.

These The object is achieved by the method for generating an analog vertical deflection signal with the features of claim 1 or by an integrated Circuit for performing solved by such a method. Advantageous embodiments are the subject of dependent claims.

Prefers is accordingly a method for generating an analog vertical deflection signal for vertically deflecting an electron beam in a picture tube a digital vertical deflection signal is provided with a waveform in a measuring range over a height over an image edge or beyond an image edge, following a return section to a height of a the border of an adjacent image area to be displayed within the image border and subsequently an image display edge to to a base height. The method is advantageous in that the return section from a height of the measuring range up to a height as a return height within the image area to be displayed and after a period of time redirected down to the heights the edge of the image area to be displayed runs.

in the Return section are the height and / or the time duration within the image area preferably variable adjustable for adjusting the vertical deflection signal to respective ones Smoothing capacitors.

Of the Return section extends preferably in the manner of a temporary jump signal in the direction of Rewind starts. Such a method is advantageous for providing the digital Vertical deflection signal by means of an integrated circuit.

Accordingly, an integrated circuit is also preferred for providing a digital vertical deflection signal for subsequently producing an analog vertical deflection signal for vertically deflecting an electron beam in a picture tube, the integrated circuit having the return jump from the digital vertical deflection signal produced and provided according to such a method.

According to the preferred The procedure thus becomes the digital vertical deflection signal a jump signal is inserted in the direction of the rewind start. This Jump signal starts after the end of the measurement lines, i. H. especially in the upper Overscanbereich, and ends before beginning of the 16: 9 picture. This Jump signal makes the deflection signal steeper in this area. The Amplitude and duration of the jump signal is preferably adjustable. This will make the filter capacitors faster during this time reloaded and the grid at the 16: 9-Bildanfang is written with correct line spacing. The adjustment is preferably made depending on the size of each selected Smoothing capacitors. Preferably, a reaction in the form of a process engineering solution possible, at which does not support the hardware of many existing circuits changed needs to be.

feasible For example, the procedure is preferably for displaying 16: 9 pictures on a picture tube, which is designed to display 4: 3 images. in principle but it is also a transmission to other dimensions possible. Depending on the type of image composition with partial images, full images or half images is possibly a transfer of the principle on a second half of the picture required, which is why descriptions of an area over a picture edge beyond in the sense of an area beyond a picture edge outside of the image are to be interpreted, so that a transfer also to areas are possible in principle below a lower edge of the picture.

One embodiment will be explained in more detail with reference to the drawing. Show it:

1 schematically a television set with various components and representations of a digital vertical deflection signal or an analog vertical deflection signal according to the preferred embodiment and

2 a digital vertical deflection signal and an analog vertical deflection signal according to the prior art.

2 shows a known digital vertical deflection signal for displaying a 16: 9 image on a 4: 3 picture tube. This digital vertical deflection signal is used to generate an analog vertical deflection signal for vertically deflecting an electron beam in a picture tube.

The digital vertical deflection signal ds starts in the displayed area with a return edge f1 from the beginning of a signal cycle from a base height ubh and performs a picture area to a height mh over a height orh of an upper edge R of the picture. In the case of the 16: 3 picture corresponds the base height ubh a lower edge of an image area B to be displayed on the picture tube 16: 9 picture, which is within an up and down picture below larger picture border of a 4: 3 picture.

following extends the vertical deflection signal ds via a measuring range m in the area above the Image border orh within the Overscanbereichs. After the measuring range m follows a return section r at a height obh one of the upper edge of the image R adjacent upper edge to be displayed image area B, wherein the image area to be displayed B again that of a 16: 9 picture equivalent. After the return section r follows an image display edge f2 down to the base height ubh. The image representation edge f2 extends obliquely, corresponding to a vertical Deflecting successive lines across the image display area.

in the Essentially, the digital vertical deflection signal ds is turned on by sawtooth signal formed, which has an inflated initial area into the overscan area has. As from the representation of a from this, analog vertical deflection signal as shown However, such a deflection signal causes a disadvantageously slow reloading of filter capacitors, since the analog vertical deflection signal as from Measuring range from not steep enough. This leads to an elongation of the upper one Edge of the image display area or the actual image area of a 16: 9 image.

1 schematically shows a television with a picture tube M, which is driven by, inter alia, an integrated circuit IC. The integrated circuit IC generates inter alia a digital vertical deflection signal ds, which is converted by means of a digital / analog converter arrangement into an analog vertical deflection signal as. The analog vertical deflection signal as is used to control an electron beam of the picture tube M. As the signal source VCR, for example, an antenna input or a video recorder can serve to provide an image signal.

Of the actual imaging surface of the picture tube M, only a section within an image edge R is actually visible. An overscan area, which is located between a height orh of an upper picture edge R and an upper height omh of the picture tube M, is obscured by a panel for the observer. In this area is the Overscanbereich with measuring lines. An appropriate Overscanbereich can also under half a height urh a lower edge R and a lower height umh the picture tube M are accordingly. With respect to the lower portion of the picture tube M and a corresponding drive, if necessary, corresponding procedures as for the upper picture area may be appropriately applied.

Of the Image border R surrounds a region for displaying a 4: 3 image on the picture tube M. Im However, the case of a 16: 9 picture to be displayed becomes only a lesser one Image area B between a lower height ubh and an upper height obh needed. The remaining Regions within the image border R above and below this Image area B remains black.

In addition to the outlined television, a time course t of the digital vertical deflection signal ds for a 16: 9 image is shown, the height designations as shown in the sketched TV and accordingly 2 are used.

Across from 2 the return portion r of the digital vertical deflection signal ds is modified. Instead of a steep as possible, preferably vertical edge from the end of the measuring range m to the beginning of the image display edge f2, the return portion r extends over a limited period b of the time course t. In addition, the waveform of the digital vertical deflection signal ds during the retrace section r reaches a height h to below the height obh of the upper picture area of the 16: 9 picture to be displayed. In other words, the digital vertical deflection signal ds during the return portion r during the limited period of time b in a height range of the image area B into it.

Preferably are the height h and the width or time duration b of the return section r individually to the size of each Screening capacities customizable. To the end of the return section r jumps the waveform of the digital vertical deflection signal ds back up obh the upper edge of the image area B.

As from the waveform of the analog vertical deflection signal shown below As can be seen, the modified return section r causes a steeper transition from the measuring range m to the beginning of the image display edge f2, so that a adulteration of a 16: 9 image to be displayed, although not specific Booster for the Return section r be used.

Claims (6)

Method for generating an analog vertical deflection signal (as) for vertically deflecting an electron beam in a picture tube (M), in which a digital vertical deflection signal (ds) is provided with a waveform in a measuring range (m) over a height (orh ) beyond an image edge or beyond an image edge (R), following a return section (r) to a height (obh) of an edge of an image region (B) to be displayed within the image edge (R) adjacent to the image edge (R) and - subsequently an image display edge (f2) up to a base height (ubh), characterized in that - the return portion (r) from a height (mh) of the measuring range (m) to a height (h) as a return height within the image area to be displayed (B ) and after a time duration (b) backwards to the height (obh) of the edge of the image area (B) to be displayed. The method of claim 1, wherein in the return section (r) the height (H) within the image area (B) is variably adjustable for Adjusting the vertical deflection signal (ds) to respective screening capacities. Method according to claim 1 or 2, wherein in the return section (r) the time duration (b) within the image area (B) variable adjustable to adjust the vertical deflection signal (ds) respective screening capacities. Method according to any preceding claim, in which the return section (r) in the manner of a temporary jump signal in the direction of a rewind start runs. A method according to any preceding claim for providing of the digital vertical deflection signal (ds) by means of an integrated Circuit (IC). Integrated formwork (IC) for providing a digital vertical deflection signal (ds) for subsequent generation an analog vertical deflection signal (as) for vertical deflection an electron beam in a picture tube (M), wherein the integrated circuit (IC) the digital vertical deflection signal with a return section (r) according to one A method according to any one of the preceding claims is generated and provided.