JPH04227392A - Television signal processing system - Google Patents

Abstract

PURPOSE:To reproduce a picture with lots of scanning lines without flickering by forming an output of an image pickup element device of sequential scanning into an interlace signal, sending the signal and allowing a reception section to reproduce the signal as the sequential scanning television signal. CONSTITUTION:A line sequential scanning signal is obtained by an image pickup device and it is converted into an interlace scanning television signal 120 by using storage circuits (scanning line buffer storage circuits) 108-110 and the resulting signal is sent. Then the receiver side converts the signal into a signal of line sequential scanning having a frame frequency being a multiple of (n) of the frame frequency of the television signal 120 to reproduce the picture. That is, the line sequential picture signal is converted into an interlace television signal comprising n-fields by one frame and the receiver side converts the television signal into a line sequential signal having a frequency being a multiple of (n) of the frame frequency of the television signal and reproduces it.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a television signal processing system,
More specifically, the present invention relates to a signal processing method for converting a television signal into a television signal that provides better image quality without causing eye fatigue.

0002

BACKGROUND OF THE INVENTION Current standard television systems employ interlaced scanning to reduce the required frequency band. As a result, flickering appears in parts of the screen that change rapidly vertically.

The reason why flickering occurs will be explained with reference to FIG. In FIG. 1, the scanning line group 1 of the first field is sequentially scanned, then the scanning line group 2 of the second field located in the middle of the scanning line group 1 is sequentially scanned, and the scanning line group 1 of the first field is sequentially scanned. 1 is scanned, and so on. Therefore, if the screen changes suddenly in the vertical direction, for example from black at the top to white at the bottom, as shown in Figure 1, the change from black to white in the first field 3 and the location of the change from black to white in the second field 4 are shifted by one scanning line interval. Therefore, the location of the change in black and white moves up and down with the frame period, which causes a flicker to appear in areas of the screen where there is a sudden vertical change.

0004

[Problem to be Solved by the Invention] The above flickering does not bother you much on a normal screen, but it becomes very noticeable on a screen where many horizontal lines are arranged regularly or near-horizontal lines are concentrated at one point. Become. It also causes eye fatigue when viewing television images for a long time.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to realize a television signal processing system for obtaining a flickering-free television signal from a television signal employing interlaced scanning.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention obtains line-sequential scanning signals with an imaging device,
This is converted into an interlaced television signal using a storage circuit and transmitted, and on the receiver side it is converted into a line-sequential scanning signal with a frame frequency n times the frame frequency of the television signal to display the image. It is designed to be played back.

[0007] In the following example, the case where interlace is 2:1, which is generally practiced at present, will be explained.
The present invention can also be implemented in the case of n (an integer greater than or equal to 2):1.

[0008]

[Operation] The present invention transmits the output of a progressive scanning imaging device as an interlaced signal, and reproduces it as a progressive scanning television signal in the receiving section. A large number of images can be played back without flickering.

[0009]

[Embodiment] FIG. 2 shows a portion of converting a line-sequentially scanned image signal output from an imaging device on the transmitting side into a 2:1 interlaced television signal in an embodiment of the television signal processing method according to the present invention. FIG. 2 is a configuration diagram showing the configuration of.

Three primary color signals 101, 102, and 103 from an imaging device that does not perform interlaced scanning, that is, sequentially scans a frame from top to bottom, are converted into a luminance signal 105 and two color signals 106 by a generally known matrix circuit 104. and 107. signal 105,
106 and 107 are read into buffer memory circuits 108, 109 and 110, respectively, each having a capacity of at least one field.

Buffer storage circuits 108, 109 and 110
reads every other scanning line to outputs 114, 115, and 116 using a timing signal 113 generated by a timing generation circuit 112 from a synchronization signal 111, and converts it into an interlaced scanning signal. The reason why it is sufficient to have a capacity of one field is that it is sufficient to write the signals that arrive sequentially in the read locations. Therefore, if a capacity for one frame is provided for each, there is no need to write to the read location, and the configuration of the timing generation circuit 112 becomes simpler. Outputs 115 and 116 corresponding to the two color signals are applied to a commonly known modulation circuit 117 and converted into a carrier color signal 118. The output 114 corresponding to the luminance signal and the carrier color signal 118 are summed by a summing circuit 119 to form a composite color television signal 120. That is, every 1/30 second 5
The 25 sequentially scanned signals are sent to the buffer memory circuit 108,1.
09,110, and since every other scanning line is read out, 262.5 signals are read out in 1/60 seconds to obtain an image signal for one field, and then the next 1/60 second signal is read out. In the meantime, the remaining 262.5 lines are read out and converted into one field signal. By repeating this process, an interlaced signal similar to a normal television signal is obtained.

In FIG. 2, even if the order of the matrix circuit 104 and the buffer memory circuits 108, 109, and 110 is reversed, the prescribed operation is performed, but since the band of the three buffer memory circuits must be made the same as that of the luminance signal, the circuit The scale becomes larger.

FIG. 3 shows a color television signal generated by the conversion circuit of FIG. 2 which is subjected to interlaced scanning, after being separated into a luminance signal and a chrominance signal by a known luminance and chrominance signal separation circuit. 2 is a drawing showing the configuration of a conversion circuit for converting into a scanning (scanning) signal.

In FIG. 3, an input signal 201 is converted into a signal 204 delayed by 1 field and a signal 2 delayed by 2 fields by two 1-field delay circuits 202 and 203.
05 is generated. The input signal 201 and the signal 204 delayed by 1 field become two inputs of the switch circuit 206, and the signal 204 delayed by 1 field and the signal 204 delayed by 1 field become the two inputs of the switch circuit 206.
The field-delayed signal 205 is sent to the switch circuit 207
There are two inputs. The switch circuits 206 and 207 are
Controlled by the vertical synchronization signal 208, if the signal delayed by one field is present in the first field, the input signal 20
1 and 1 field delayed signals 204 are connected to outputs 209 and 210, respectively. Further, when the signal 204 delayed by one field is present in the second field, the signal 204 delayed by one field and the signal 205 delayed by two fields are outputted to outputs 209 and 210, respectively. Therefore, the same frame, second field, and first field always appear in the outputs 209 and 210.

The outputs 209 and 210 are converted into a signal 225 without interlaced scanning by scanning line buffer storage circuits 213 and 215 and a switch circuit 224.

The signal conversion operation of the receiving section will be explained using the waveform diagrams of FIGS. 4 and 5.

FIG. 4 shows the switch 20 of FIG. 3 for convenience of explanation.
6,207 is in the upper position. (Things that are the same as those in FIG. 3 are given the same numbers).

As mentioned above, the signals 209 and 210 are generated from the second field and the first film in the same frame, respectively, and depending on the relationship between the number of scanning lines and the field period, they are separated by 180 degrees as shown in FIG. There is a phase difference so that adjacent scanning lines exist at the same time.

Both buffer memory circuits 213 and 215 are
A memory circuit that has a storage capacity of at least half the pixels of one scanning line, and is capable of independent writing and reading speeds, and is composed of semiconductor random access memory integrated circuits, magnetic core random access memory devices, etc. Storage capacity is 0.5
The reason why a scanning line is fine is that after reading out the remaining portion, it is sufficient to sequentially read the remaining portion. Therefore, if a storage capacity for one scanning line is provided, there is no need to write data after reading, and the control circuit for buffer storage circuits 213 and 215 becomes simpler.

In order to drive these buffer memory circuits 213, 215 and switch circuit 224, the television signal 20
A horizontal synchronizing signal 227 is separated from the horizontal synchronizing signal 227 by a synchronizing signal separating circuit 226, and is used to generate a clock signal 229 synchronized with the horizontal synchronizing signal in a clock generating circuit 228 to control writing. Also, reading is performed at twice the speed of the above clock signal. A synchronization signal 2 having half the period of the horizontal synchronization signal is generated from the horizontal synchronization signal separated by the multiplier 230.
31 and controls the switch circuit 224.

[0021] Therefore, the television signals 201 and 20
4 to the center of the scanning line in buffer memory circuits 213 and 215 with a 0.5 scanning line capacity, respectively, and the waveforms 213' (broken line) and 215 (solid line) in FIG. If the reading speed is doubled as shown in FIG. A converted television signal 225 is obtained without performing interlaced scanning for one frame.

The present invention has been explained above using examples, but
The present invention is not limited to the above-mentioned embodiments, and the present invention includes application only to the luminance component of a television signal or the low frequency portion of the luminance component, as long as image quality permits. Further, although the embodiments have been described with respect to a 2:1 interlaced television signal, the present invention generally also applies to n:1 interlaced television signals. In this case, the conversion circuit on the transmitting side requires buffer storage circuits for at least (n-1) fields, and the receiving side requires 2(n-1) field delay circuits.

Furthermore, although the circuit of the present invention has been explained without distinguishing between analog processing and digital processing, when performing processing involving digital processing and sampling,
An AD conversion circuit, a DA conversion circuit, and a filter circuit are required. However, how to use these circuits is
Since this is common knowledge for engineers in related fields, I have omitted the explanation.

[0024]

Effects of the Invention The present invention transmits the output of a progressive scanning imaging device as an interlaced signal and reproduces it as a progressive scanning television signal in the receiving section. Images with many lines can be played back without flickering.

[Brief explanation of the drawing]

[Figure 1] Drawing explaining conventional interlaced scanning

FIG. 2 is a diagram showing the configuration of signal conversion circuits on the transmitting side and receiving side in the television signal processing system according to the present invention.

FIG. 3 is a diagram showing the configuration of signal conversion circuits on the transmitting side and receiving side in the television signal processing system according to the present invention.

[Figure 4] Configuration diagram of the signal conversion circuit shown in Figure 3 above

[Figure 5] Waveform diagram showing the operation of Figure 3

[Explanation of symbols]

104...Mathrix circuit, 108, 109, 110...
Buffer storage circuit, 112... Timing generation circuit, 117... Modulation circuit, 202, 203... Field delay circuit, 213,
215...Buffer memory circuit.

Claims (1)

[Claims] 1. A transmitting side converts a line-sequential image signal obtained by an imaging device into an interlaced television signal in which one frame consists of n fields, and a receiving side converts the television signal into an interlaced television signal whose frame frequency is the same as that of the television signal. A television signal processing method that converts an input first television signal into a line-sequential scanning signal with n times the frame frequency of
a second television signal delayed by one field from the first television signal; and a third television signal delayed by two fields from the first television signal.
When the second television signal is a signal of the first field, the first and second television signals are obtained, and when the second television signal is a signal of the second field, the above television signal is obtained. Select two television signals from the first, second, and third television signals such that a second and third television signal are generated, and halve the time of each of the two selected television signals. A television signal processing method that converts the two compressed television signals into a time-series television signal by switching alternately on a scanning line basis.