JPS5970369A - High definition/standard television converting system - Google Patents

Abstract

PURPOSE:To attain ease of conversion to the standard system, by deciding the number of scanning lines and frame number of the high definition television system so as to satisfy a prescribed subsequent condition to the standard system, while keeping the conditions required for the transmission and display of picture information with high definition. CONSTITUTION:An HDTV signal applied from a terminal T1 is separated synchronizingly and a video signal component is applied to an A/D converter 2 so as to obain an encoded HDTV signal. One of the HDTV signal is extracted at each m-set of signals at a switcher 3 and transferred to a line memory 4. The line memory 4 is a memory possible for readout and a signal written from a readout terminal T3 is read out by being expanded at one line period. This readout signal is applied to a synchronizing adder 6 via a D/A converter 5 and the information required for the horizontal and vertical synchronism is added at the converter 5 and the signal becomes an output signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high definition/standard television conversion system that allows conversion from a high definition television system to a current standard television system using simple equipment.

Traditionally, in order to facilitate the format conversion between high-definition television and standard television phase η, high-definition television power type scanning! ! It has been considered desirable to have a system in which the number 9 is an integral multiple of the number of scanning lines of the standard television system. Therefore, conditions that are easy to replace are essential (-In the fourth case, the number of scanning lines in the high-definition television system was subordinate to that in the standard television system. The standards for two-dimensional image information required for television, such as the number of pixels per scan and the ratio of pixels, are set from a different perspective than the standards for standard television. - In F with strict dependent conditions such as those mentioned above, h
It will be difficult to establish a suitable high-definition television standard. However, certain dependent conditions are required to enable easy conversion to the standard system.

Therefore, the purpose of the present invention is to satisfy certain dependent conditions with the standard method while maintaining safe conditions for transmitting and displaying high-quality two-dimensional internal image information. 1. ``Setting the number of scanning lines and frames for i-definition television'')j: By doing so, it is easy to convert to the standard format.
The purpose is to provide a standard television conversion method.

In order to achieve such a goal of 1", in the present invention, the number of scanning lines nH and frames of a high-definition television system are 7", where the number of scanning lines of a standard television system is ns and the frame frequency is fps. Frequency fp+ is ns @ fpH= me ns * f
ps, where m is set to be a positive integer greater than or equal to 2, which is fpH 1,000 fps, and is compatible with high-quality images, and
At least a line selection circuit for adding a substantial l line to an m line 4T4- for an image signal based on a high-definition television system, and a line time expansion circuit for expanding a signal of the selected line to at least m line time. an image signal processing circuit; and a synchronization signal for generating a second synchronization signal related to the high definition television output type synchronization signal and adding the second synchronization signal to the signal converted by the image signal processing circuit. The present invention includes at least a processing circuit for converting a high-quality image signal according to the "t-television system" into an image signal having the number of scanning lines of the standard television system.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a 41' high-definition television power system according to the present invention.
The i standard is compared with the signal waveform of the standard television system. First, in the high-definition television system, the information of the two-dimensional image, the number of scanning lines, and the number of pixels are determined depending on the application. For example, when viewing a television from a distance 2.5 times the screen height, the number of scanning lines is approximately 1,480, and when viewing from a distance three times the screen height, the number of scanning lines is approximately 1,125. It is known from research by the present inventors that the number of scanning lines is necessary.

Therefore, for such a high-definition television system with a predetermined number of scanning lines, the present invention does not set the number of scanning vI dependently on the number of scanning lines of the standard television power system as in the past. , the field frequency and frame frequency are chosen such that the water'sF scanning frequency is an integral multiple of the horizontal scanning frequency of the standard television system. In other words, if the number of scanning lines in the standard I television system is ns, the frame frequency is fps, the required number of scanning lines in the high-definition television system is nH, and the frame frequency is fpH, then the following equation (1) is obtained. You get a relationship.

nH * fpH = mens * fps (
1) However, ■ is a positive integer that is 2 or more and under the condition that fpH does not change more than fps.

For example, as mentioned above, set the viewing distance to 2.5 of the screen height.
In a system with double nH = 1480 lines, m-:3, fpH = 525 meters x 30 sheets x 3 / 1480 =
In a system of nH=1125 trees where the viewing distance is 31.9257Hz and the viewing distance is 3 (;'x, m=2, fpH=28.0Hz.

In this way, if fps is close to fps (30Hz), for example 28-32) 1z, then when m = 2 (7), approximately 984 < n.

< 1125 tons, approximately +47fl when Tn=l
<nH<1688, which increases the degree of freedom in selecting nH.

Figures 1 (A) and (B) show a comparison of line signals between these high-definition television systems (abbreviated as IDTV) and standard television systems (abbreviated as STIR-TV) when m = 3. 1, and FIGS. 1(C) and 1(D) similarly show the relationship of frame signals between the two.

Here, since the horizontal scanning period of ) IDTV and 5TD-TV has a simple proportional relationship of I.3, for example, as shown in Figure 2, the conversion from ) HDTV signal to 5TD-TV is This can be done extremely easily using a simple line memory that can be read and read. That is, one line out of every three lines of the HDTV signal shown in FIG. 1(B) is taken out by a switcher as shown in FIG. 21(A), and this switcher output is written into a digital line memory. rB), it is slowly read out in three times the time via a line time expansion circuit, and the phase shown in Figure 1 (A) is read out slowly.
Also take out the signal.

- Taking into account that the aspect ratio of HDTV is wider than that of 5TD-TV, for example 3:5, in this case, as shown in Figure 3 (A), an old HDTV
The part of the HDTV signal corresponding to the aspect correction of 5TD-TV is converted to 5T by a line time expansion circuit.
94748 with the required aspect ratio of 5TD-TV stretched in time as shown in the third UA (B).

Figures 1 and 4 are examples of configurations showing the system conversion described in (2) below, including a synchronization signal conversion processing circuit system. 1. Separate the synchronization signal and video signal.

The separated video signal components are supplied to an A/D converter 2 to obtain an encoded HDTV signal. This HDTV
Regarding the signals, as described above, m HDTV signal line signals are allocated to one line period of the 5TD-TV signal. Therefore, the switcher 3 extracts every m HDTV signals from the A/D converter 2 and transfers them to the live memory 4. This line memory 4 is a writable and readable memory, and its -: input signal to the write terminal T2 is shown in FIG. 2(A) or FIG. 3(A). S T D - T V (i
In the horizontal scanning period of No. 1, write the 1-line signal of HDTV a with the aspect correction that you want to display. Further, at the read terminal T3 of the memory 4, this written signal is read out after being extended by one line period of the ST[1-TV signal. The read output signal is supplied to the D/A converter 5 and converted into an analog signal. This analog signal is supplied to the synchronization adder 6, and information necessary for synchronization and vertical synchronization obtained as described later is added thereto, and the resultant signal is outputted from the terminal T6 as an output signal.

In the figure, 7 is a pulse generator that generates pulses at a frequency twice or three times that of the HDTV signal t) according to the value of m mentioned above, and with respect to the horizontal scanning frequency fHH of the HDTV signal,
m/fHH pulse generator. This pulse generator 7
The synchronization signal taken out from the synchronization separation circuit 1 is supplied to synchronize the phase of the oscillation pulse with the f++ phase of the HDTV signal. 8 is a vertical synchronization position separation circuit which extracts the 1 (DTV TV signal direct synchronization pulse) from the synchronization signal taken out from the synchronization separation circuit 1, and applies this IF direct synchronization pulse as a reset pulse to the counter circuit 9. The output from the generator 7 is counted down by an appropriate value to create a vertical synchronization signal.This vertical synchronization signal is supplied to the synchronization adder 6 and added to the conversion signal from the +1/A converter 5. Output from 1.
-8 is counted down by the 172m counter circuit 10 and supplied to the synchronization actuator 6 as a horizontal synchronization signal of the conversion signal from the D/A converter 5.

Here, regarding the counter circuit 9 and its output signal, taking a system where m=2 as an example, further: 'V #l
1 pleasure per n. FIGS. 5(A) to (D) are −]--the above n+=l125 HDTVs m=2. fpH
= 28.0 This shows a television raster pattern of the present invention system. In this case, the pulse generator 7 shown in FIG. 4 generates 2 f HH. Figure 5 (A) shows nH
Figure 5 (
B), (C) and (D) show rask patterns obtained by performing various types of vertical synchronization No. 1.1 processing on signals converted to 5TD-TV. First, FIG. 5(B) shows the HD obtained every T'H=1125 as the output of the counter circuit 9.
The vertical synchronization signal of the TV is directly added to the conversion signal, and the scanning returns to the original in 5 fields. This is shown in waveforms as shown in FIG. 6(C). FRM here
is a frame pulse, and FLD is a field pulse.

However, the horizontal synchronization signal is omitted. In this case, there is a drawback that correct interlaced scanning images cannot be obtained within the -field and even-numbered fields. Next, as shown in FIG. 6(D), the counter circuit 9 is set to n+ + in the first field.
Count from 1 = 1126.

In the second field constituting one frame, ns
-1 = 1124 counts. The rask pattern obtained in this case is as shown in FIG. 5(C), and has a correct interlaced form in terms of tail and scanning. Therefore, it is easier to see the line tension of the image displayed by transformation I, -1 in FIG. 5(C) than in FIG. 5(B). but,
In FIG. 5(C), the scanning lines 563, 565, 5 shown in the figure are
As can be seen from the comparison with Fig. 5 (A), the information in 67 is reproduced with a shift of one scanning line on an HDTV, so the content of one image is not displayed on the screen. The display will not be displayed S, and the resolution in the vertical direction will deteriorate.

FIG. 5(D) shows a converted signal that further improves this defect. Regarding the original HDTV signal, the A field of one field of the frame, for example, the A field of the I and a half, is different from the previous line. A signal with an average value (n + n ÷ 1) / 2, that is, a linear interpolation signal, is added to these 4:j, p and a vertical synchronization signal similar to that in Figure 5 (C) is used as a conversion signal. . FIG. 5 (CG) shows the rask pattern in this case, and the quality of the reproduced image in this case is improved compared to the case in FIG. 5 (C).

Here, FIG. 7 shows an example of the circuit layout for implementing the scanning form that provides the rask pattern shown in FIG. 5(D), and the signal waveforms of each part are shown in FIGS. .

In FIG. 7, the same reference numerals are given to the same parts as 4 (Δ). In this example, the output from the A/D converter 2 is connected directly to the selector switch 11 or to the IH memory and the adder 13. The switch 11 is connected to the switcher 3 through a system consisting of a 2 divider! Directly connected fields, e.g.
The operation in the first field shown in ) is the same as in FIG. That is, as shown in FIG. 6(A), the frame pulse FRM and field pulse FLD are
When an HDTV signal is applied to the input terminal T1, the switcher 3 thins out the video signals of the odd lines and writes them into the memory of the line time expansion circuit 4. The written signal is delayed by IH as shown in FIG. 6(B), and by slowly reading out the written signal from the memory, the time is expanded as shown in FIG. 6(C). A line signal is obtained. For this line signal train, as shown in FIG. 6(D) or (E), the count value of the counter circuit 9 is switched to nH±1 in the field 40°, that is, 1126 and 1124 as described above. Synchronize the frame pulse 7, FRM and field pulse FLD and horizontal sync pulse to the adder 6.
Add in. For the latter field, the switch 11 is changed and the output from the A/D converter 2 is sent via the IH memory 12 and directly to the adder 13.
, and after being added here, it is then halved by the 172 divider 14 to give the intermediate balance between the two lines (
The signal of n+ n++ )/2 is set to 1. This signal 7r
i 6th jA (E) 51311/1565.5H
/158? , -...etc. shapes! It's z14. The process of adding vertical and horizontal synchronization signals to the white line interpolation signal is the same as the process already performed.

In the present invention, as described above, the HDTV signal is
i7) is shown in Figure 6 (C), (0) is (E)
Convert to a signal in the form shown in Figure 4 or 7.
It is taken out from the illustrated output terminal T6. In this way 11
Since the field frequency and frame frequency in the extracted system conversion signal are the field frequency and frame frequency of the high-definition television system, the standard is 1.
1 Although slightly different from the television system, water-[i
The scanning frequency is converted to standard television format and rotation signals using a simple device such as a one-line memory. In general, television receivers do not operate even if the horizontal scanning frequency fluctuates even slightly, but the vertical scanning frequency is operated using a circuit with a wide response band, so fp
, fF (field frequency) changes.
15) The converted signal produced by the present invention can be used to reproduce television images on a standard television receiver.

That is, the present invention achieves this by determining a high-definition television system from necessary two-dimensional image information and by obtaining a high-definition television system that can be easily converted into a standard television system.

As is clear from the above, according to the present invention, conversion from a standard television system can be achieved using a simple configuration such as a line memory while maintaining the ability to reproduce two-dimensional image information, which is most necessary for a product IM television system. Therefore, it is promising as a future television system.

[Brief explanation of the drawing]

Figures 1 (A) to (D) are signal waveform diagrams for explaining the scanning standards of the standard television system and high-definition television system, and Figures 2 (A) and (B) are signal conversion in the present invention. A signal waveform diagram for explaining the principle of processing; FIGS. 3A and 3B are partially enlarged views; FIG. 4 is a block diagram showing an example of a circuit arrangement for implementing the present invention; FIG. Figures (A) to (D) are diagrams showing raster patterns in various examples of system conversion signals according to the present invention, and Figures 6 (A) to (E) are signal waveform diagrams showing various examples according to the present invention. FIG. 7 is a block diagram showing another example of a circuit arrangement for implementing the present invention. DESCRIPTION OF SYMBOLS 1... Synchronous separation circuit, 2... A/D converter, 3... Nuinnaya, 4... Line memory, 5... D/A converter, 6... Periodic adder, 7...・Pulse generator, 8... Vertical synchronization position Separation circuit, 9... Counter circuit, lO... Bow/2m counter circuit, 11... Switch, 12... IH memory, 13... Adder , 14... Bow 72 divider. \ Town 0 Q \, \J -ノ
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Claims (1)

[Scope of Claims] l) When the number of scanning lines of the standard 1° television system is ns and the frame frequency is fps, the scanning line anH and frame frequency fp of one television system are high quality.
+ is defined as nH11fpH=m・n5IIfpS where m is a positive integer of 2 or more that is fps and corresponds to a high-quality image, and the m line 4t5 is set for the image signal by the high-definition television system. A line Hikone circuit that selects a substantial line and a signal of the selected line at least m
an image signal processing circuit comprising at least a line time expansion circuit for expanding line time; and generating a second synchronization signal related to a synchronization signal of a high definition television system;
and a synchronizing signal processing circuit for converting the synchronizing signal of the image value into the image signal processing circuit and adding it to the image signal processing circuit 7'j ++i-''3, the image signal according to the high definition television system is A high-definition/standard television conversion method in which conversion into an image signal having the number of scanning lines of the standard telephony system is 11 (1+). 2. In the high-definition/standard television conversion method according to claim 1. , a high-definition/outside-frame television characterized in that the length of the substantial one line extending in time is set according to a difference in screen aspect ratio between the standard television system and the high-definition television system. Conversion method. 3) i'j described in claim 1 or 2
In the i-definition/standard television conversion power system, the synchronizing signal processing circuit converts the feel of either one of the sound evens when 1m is an even number. A high-definition/standard TV/vision conversion method that is characterized by giving 4) I! f, i4 In the high-definition/standard television conversion system as set forth in claim 3, the image value processing circuit includes an interpolation signal between adjacent lines, 1y1 to the field giving the offset. A high-definition/standard television conversion method further comprising an interpolation processing circuit for forming.