JPS628695A - Recording and reproducing device for color television signal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention separates a color television signal to be recorded into a chrominance signal and a luminance signal, frequency converts the chrominance signal to a low frequency band, and converts the luminance signal into its chrominance signal. This relates to a color television signal recording and reproducing device that performs frequency modulation to a frequency band above the frequency band of a low-pass converted color signal, mixes both, and then simultaneously records and reproduces the same onto the same recording track of a recording medium. be.

Recording and reproducing of color television signals using the conventional color signal low frequency conversion method is currently widely used in consumer VTRs. In order to increase the resolution of this type of VTR, there is a method of shifting the carrier wave for FM modulation of the luminance signal to an upper frequency band during recording and expanding the lower side wave band of the FM modulation wave. Another method is to return the high-frequency component of the luminance signal to the low-frequency side, record it within the transmission band of a conventional VTR, and then return it during playback to improve the horizontal resolution.

Problems to be Solved by the Invention However, with the former method, the conventional VTR
The tapes are not fully compatible. Although the latter method provides full compatibility with conventional VTRs, it requires the use of a memory element during playback, making the circuit configuration complex and expensive.

As described above, the conventional method has problems with the complexity of the circuit configuration for improving the image quality of the luminance signal, an increase in cost, and compatibility with the current method.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a color television signal recording and reproducing apparatus that has a simple configuration and is compatible with current recording and reproducing apparatuses.

Means for Solving the Problems In order to solve the above problems, the present invention minimizes the shift of the FM modulated wave of the luminance signal during recording to the upper frequency band, and provides a low-frequency converted color signal. The components of the low-pass filter for color signals that determines the upper limit frequency of the FM-modulated luminance signal and the high-pass filter for the luminance signal that determines the lower limit frequency of the FM-modulated luminance signal are varied, and the passband of each of the filters is made variable. The recording luminance signal band is widened when necessary, and the resolution of the luminance signal is increased.

Effect of the Invention With the above configuration, the present invention expands the lower side wave band of the FM modulated wave of the luminance signal during recording when high-resolution recording and reproduction is required, thereby increasing the resolution of the luminance signal and improving dubbing characteristics. can be easily realized.

Embodiment FIG. 2 shows a frequency spectrum arrangement in an embodiment of the color television signal recording and reproducing apparatus of the present invention. FIG. 2(a) shows the case of normal recording in the current system VTR, and FIG. 2(b) shows the case of high resolution recording. (b) In the figure, the shift of the FM modulated wave of the luminance signal to the upper frequency band) (from f3-f to f3-f4) is kept to a minimum (for example, 100 KHz to 300 KHz), and the passband of the color signal filter is changed from f6 to By lowering the brightness into a bow and changing the normal band of the brightness signal filter, the lower sideband of the brightness signal FM modulated wave is widened and the resolution of the brightness signal is improved.

FIG. 1 is a circuit diagram showing an embodiment of a recording color signal low-pass filter used in the present invention. In FIG. 1, 1 is an input terminal to which a low-frequency converted color signal is applied during recording; 2
is the output terminal. For normal recording, switch SW1
is OFF, transistor Tr1 is also OFF, and capacitor C4 is connected to resistors R1, R2, capacitors CI and C2.
, C3, inductor L1. It is not connected to the low-pass filter circuit 3 consisting of L2, and its characteristic becomes curve A in FIG. During high-resolution recording, the switch SW1 is turned on, the transistor Tr1 is also turned on, and the capacitor C4 is connected in parallel to the inductor L2. As a result, the characteristics of the low-pass filter circuit 3 are curved as shown in curve B in FIG. The high frequency portion of the passband indicated by A has a characteristic that is rapidly attenuated, and the passband becomes narrow.

FIG. 4 is a circuit diagram of an embodiment of a high-pass filter for an FM modulated wave of a luminance signal used during recording according to the present invention. 4
5 is an input terminal for a luminance signal FM modulated wave, and 5 is an output terminal. In the case of normal recording, the switch S'W'2 is OFF and the transistor Tr2. Both Tr3 are turned off, and capacitors C4 and C5 are connected to resistors R1, R2, R3, R4, and VRl.
, capacitor CI, C2, C3, inductor L1. L2
It is not connected to the high-pass filter circuit 6 consisting of. In the case of high-resolution recording, the switch SW2 is turned on, and as a result, the transistors Tr2. Tr3 both turn ON,
The capacitor C4 is connected in parallel to the capacitor C1, and the capacitor C6 is connected to the capacitor C2 in parallel, so that the pass band extends toward the lower frequency side, as shown by the characteristic of the high-pass filter 6 as shown by the curve C in FIG. As a result, F of the luminance signal
When the lower sideband of the M modulated wave is expanded and demodulated, the resolution of the luminance signal increases. During high-resolution recording or normal recording, the switches SW1 and SW in FIGS.
The ON and OFF operations of 2 are performed at the same time.

FIG. 6 shows another embodiment of the high-pass filter circuit used in the present invention, in which both switch SW3 and switch SW4 are turned on during high-resolution recording, and resistors R1, R2, R3,
R4, VRl, :+77' fC1, C2, C3,
Inductor L1. High-pass filter circuit 7 consisting of L2
capacitor C4 to capacitor C1, inductor L3
By connecting both in parallel to the inductor L2, the characteristics shown in Fig. 6 can be obtained.

Effects of the Invention As described above, the present invention has a very simple and inexpensive configuration, is fully compatible with the current VTR system, and can change the resolution of the luminance signal when necessary, without compromising the fidelity of the color signal. Therefore, the dubbing performance can also be improved, which is extremely effective in practical terms.

[Brief explanation of the drawing]

1 and 4 are electrical wiring diagrams of a low-pass filter and a high-pass filter used in an embodiment of the color television signal recording and reproducing apparatus of the present invention, respectively, and FIG. 2 is an electrical wiring diagram of a high-pass filter of the present invention. This figure schematically shows the frequency spectrum arrangement of a recorded signal in an embodiment of a color television signal recording/reproducing device, in which (a) is a characteristic diagram for normal recording, and (b) is a characteristic diagram for high-resolution recording. 3 and 6 are characteristic diagrams of the filter circuit, respectively, and FIG. 6 is an electrical connection diagram of a high-pass filter in another embodiment of the present invention. 1.4...Input terminal, 2,6...Output terminal, 3...Low pass filter, 6...
High pass filter. Name of agent: Patent attorney Toshio Nakao and 1 other person f゛-゛λjJ Hanawa 1 Figure 2: 1 sentence - Figure 3: 7%! 1 comparison - Figure 4 + B

Claims (1)

[Claims] frequency converting means for separating a color television signal to be recorded into a color signal and a luminance signal and converting the frequency of the color signal to a low frequency band; Frequency modulation means selectively performs frequency conversion using a high second carrier wave, and the low frequency conversion color signal output of the frequency conversion means are inputted, and a signal in a first frequency band and a high frequency signal in the first frequency band are inputted. a variable low-pass filter that selectively passes a signal in a second frequency band whose frequency portion is rapidly attenuated; a variable high-pass filter that selectively passes a signal and a signal in a frequency band higher than the second frequency band; a means for mixing the outputs of the variable low-pass filter and the variable high-pass filter; and a mixed output thereof. A color television signal recording and reproducing device comprising a recording and reproducing means for recording and reproducing on a recording medium.