JP4045204B2 - Television receiver - Google Patents

Description

[0001]
The present invention relates to a video display apparatus, and more particularly to a technique for adjusting image quality in a display apparatus capable of displaying service information such as an electronic program guide (EPG) .
[0002]
[Prior art]
A conventional television receiver will be described with reference to FIG. FIG. 6 is a schematic block circuit diagram of a conventional television receiver. In FIG. 6, an image signal (hereinafter referred to as a PI signal) is an analog signal, and a radio wave signal received by the antenna 20 is input to the demodulation circuit 3a via the tuner 1 and the IF circuit 2, and then the video 7 · Processing was performed by the chroma processing circuit 7.
[0003]
On the other hand, image information such as EPG, PPV (Pay Per View), that is, Service Information (hereinafter referred to as SI) signal is a digital signal, and is manufactured and amplified separately from the PI signal by the microcomputer M or the like. It was transmitted as an on-screen display signal. Accordingly, the PI signal and the SI signal are demodulated separately.
[0004]
The separately demodulated PI signal and SI signal are superimposed by the superimposing unit 10 and input to the display unit 11 as an output signal through the output unit 9 and displayed. In the conventional television receiver of such a system, the image quality adjustment of the image is performed by the adjustment unit Ra, specifically “knob”, in the image quality adjustment circuit 7a of the video / chromatography processing circuit 7 before the superimposition unit 10 superimposes. The control is performed by the user's adjustment, so that the image information display and the image quality are completely unrelated.
[0005]
Various methods have been put to practical use as an on-screen circuit for displaying SI signals, and a display character signal insertion circuit method for shunting color output, and switching the Y input to color output to on-screen RGB for SI signal There was a system such as a circuit for displaying.
[0006]
[Problems to be solved by the invention]
In the system where the image information display and the image quality adjustment are completely unrelated, the user cannot control the SI display, and thus there is a problem that the SI display may not be performed with the luminance according to the surrounding situation. There was no fear that the user could not display the SI display due to incorrect adjustment.
[0007]
On the other hand, recently, for example, superposition of PI signals and SI signals in a digital broadcast compatible television will be described.
The PI signal and the SI signal are mixed in a digital compression transmission system such as MPEG, for example, and transmitted / received at the same time, and then decoded by a digital decoder 4 via an antenna 20, a tuner 1 and a digital demodulation circuit 3, and then video / chroma. Processing was performed in processing 7 and output / displayed. In this system, image quality adjustment is performed by the video / chroma processing circuit 7 on the mixed signal.
[0008]
This system has a problem that the SI display may be lost due to the influence of the image quality adjustment circuit.
Since digital broadcasting tends to increase in the future, it is predicted that control of SI information corresponding to the disappearance of this SI display will become an increasingly serious problem.
[0009]
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to display an SI signal in an easy-to-see manner even in a television receiver capable of image quality adjustment by the user even if the image quality adjustment is performed by the user. It is to provide a technique for making it happen.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a television receiver according to the present invention includes a tuner for receiving a digital television signal including an image signal and a service information signal such as EPG information, and an image received by the tuner. A digital demodulator for demodulating the signal and the service information signal, a digital decoder for decoding the image signal demodulated by the digital demodulator and the service information signal, and a first image corresponding to the decoded image signal; A display unit that can display the second image corresponding to the decoded service information signal in a superimposed manner, and a superposition period between the first image and the second image is detected, and the superposition period is indicated. a detecting means for outputting a control signal, and a user adjustment circuit for adjusting the color intensity of the display image, based on a control signal from said detecting means, said heavy It characterized in that it has a prevention means for preventing the user adjustment by the user adjustment circuit in the period, a.
[0011]
In addition, a television receiver according to the present invention includes a tuner that receives an image signal and a service information signal as a digital television signal, and a digital demodulator that demodulates the image signal and the service information signal received by the tuner. A digital decoder for decoding the image signal demodulated by the digital demodulator and the service information signal, a first image corresponding to the decoded image signal, and a second image corresponding to the decoded service information signal A display unit that can be displayed in a superimposed manner, a user adjustment circuit for adjusting the color intensity of the display image, and the first image and the second image are superimposed on the display unit. And a preventing means for preventing user adjustment by the user adjusting circuit with respect to the second image.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.
[Embodiment 1]
1 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention, FIG. 2 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention, and FIG. 4 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention, FIG. 4 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention, and FIG. 1 is a schematic block diagram of a high-definition display device according to an embodiment.
[0021]
In FIG. 1, 1 is a tuner, 3 is a digital demodulator, 4 is a digital decoder, 7 is a video / chroma processing circuit, 7a is an image quality adjustment circuit, Ra is an adjustment unit, 9 is an output unit, 13 is a changeover switch, 20 is An antenna S ₁ is an ON / OFF signal indicating a superimposition period of the PI signal and SI signal detected by the digital decoder.
[0022]
In the figure, a transmission radio wave obtained by mixing a PI signal and an SI signal that are DCT processed, quantized, and encoded at the transmission source is input to the antenna 20. For example, even when a 12 GHz band SHF is used for the transmission radio wave , it can be generally received by a parabolic antenna having a diameter of 20 to 30 cm.
The tuner 1 selects and amplifies a radio wave to be received by the tuner 1 for frequency conversion. The tuner 1 is an electronic tuner that electronically switches a tuning frequency using a variable capacitance diode of an LC resonance circuit and a switching diode that switches L of the LC resonance circuit.
[0023]
The frequency-converted PI signal and SI signal are subjected to synchronous detection or delay detection in the digital demodulator 3, and are applied to digital modulation methods at the time of transmission, for example, VSB, ASK, FSK, PSK, QAM, and FDM. Correspondingly demodulated. At this time, transmission errors caused by external influences during transmission are also corrected.
[0024]
For example, in the MPEG system, the demodulated digital signal, the PI signal and the SI signal are input to the digital decoder 4 in a packet data structure, so that both can be distinguished. The digital decoder 4 decodes the PI signal and the SI signal, and the decoded PI signal is subjected to processing such as frequency conversion for each of the stationary signal and the motion signal, and is converted into an analog signal by the D / A converter. , U and V signals.
[0025]
On the other hand, an SI signal, for example, an EPG signal, is also layered on the PI signal and output as a data signal. In this case, the overlapping period of the PI signal and the SI signal is detected by the digital decoder 4 from the timing of the packet data structure, and is output to the outside as the ON / OFF signal S ₁ .
[0026]
The Y, U, and V signals from the digital decoder 4 are input to the video / chroma processing circuit 7. In the video / chroma processing circuit 7, Y, U, and V signals are inputted, and although not shown individually, the video / chroma processing circuit 7 passes through an image quality adjustment circuit 7a comprising a color density adjustment circuit, a hue adjustment circuit, and a brightness adjustment circuit. , G and B signals. A signal from the video / chroma processing circuit 7 is amplified by an output circuit 9 and input to a display display device 11 such as a cathode ray tube to drive the display display device 11.
[0027]
The image quality adjustment is performed by user control by adjusting the amplification degree of each adjustment circuit of the color density, hue adjustment, and brightness adjustment. A changeover switch 13 is provided in the operation unit of the user control. The changeover switch 13 is operated by the ON / OFF signal S _{1 in} which the PI signal and the SI signal are superimposed.
Further, the color difference signal from the video / chroma processing circuit 7 becomes a beam current m in the output circuit 9 and is input to the image receiving circuit via the synchronization / deflection circuit to form an image.
[0028]
The function of the high-definition display device having the above configuration will be described.
In the high-definition display device, the ON / OFF signal S ₁ indicating the overlapping period of the PI signal and the SI signal is detected in the digital decoder 4 by timing control. Further, as described above, the changeover switch 13 is provided in the operation unit of the user control connected to the image quality adjustment circuit 7a in the video / chroma circuit 7 via the adjustment unit Ra.
[0029]
When the ON / OFF signal S ₁ is “ON”, that is, when both signals are superimposed (hereinafter referred to as “ON”), the switch 13 is operated on the left side in the figure, and the user control side is in the “OFF” position. Thus, it is impossible to control color density and brightness by user control.
[0030]
When the ON / OFF signal S ₁ is “OFF”, that is, when both signals are not superimposed (hereinafter referred to as “OFF”), the switch 13 is operated on the right side in the figure, and the user control side is in the “ON” position. Thus, it is possible to control the color density and brightness by normal user control.
In this way, user control cannot be performed when there is an SI signal. Therefore, the screen display of the SI signal does not disappear due to the influence of the image quality adjustment by adjusting the PI signal.
[0031]
The high-definition display device according to the present invention is not limited to the high-definition display device described in the [embodiment] of FIG. 1 having the above-described configuration, and there are many other embodiments, all of which are the present invention. It is included in the technical idea. Hereinafter, several examples of other embodiments will be described with reference to FIGS. 2 to 5.
[0032]
[Embodiment 2]
With reference to FIG. 2, another embodiment of the high-definition display device according to the present invention will be described.
In FIG. 2, in the high-definition display device, a PI signal and an SI signal are provided in the video chroma circuit 7 at a preceding stage of the image quality adjustment circuit 7a, and the PI signal and the SI signal are separated by the separator 7c. To be separated. Further, a changeover switch 13a is provided at a connection portion between the video / chroma circuit 7 and the output circuit 9, and the SI signal bypass circuit 15 is provided between the image signal PI and SI signal separation portion 7c and the changeover switch 13a. Is provided.
[0033]
In the above configuration, the ON / OFF signal S ₁ indicating the superposition period detected by the timing control in the digital decoder 4 is turned ON so that the changeover switch 13a is positioned on the lower side indicated by the dotted line in the figure, and the bypass circuit 15 Only the SI signal is input to the output device 9 through the bypass circuit 15. Therefore, there is no possibility that the SI display disappears.
[0034]
When the ON / OFF signals S ₁ is "OFF", is positioned on the upper side showing a change-over switch 13a in the illustrated solid line, the bypass circuit 15 becomes the position of "OFF", the bypass circuit is shut off, PI signal Only input to the output unit 9. The image quality can be adjusted by adjusting the adjustment unit Ra by normal user control.
[0035]
[Embodiment 3]
With reference to FIG. 3, still another embodiment of the high-definition display device according to the present invention will be described.
In FIG. 3, a detector for the output beam current m of the output device 9 is provided as a detector for detecting the brightness of the display display screen in the high-definition display device. The detection can be easily performed by detecting the output current of the power supply circuit 9b.
[0036]
Further, the change-over switch 13b is provided for operating in ON / OFF signals S ₁ indicative of the overlap period to the connection line of the adjustment part Ra of the image quality adjusting circuit 7a of a video chroma processing circuit 7 is adjusted by the user control.
[0037]
Wherein when ON / OFF signal S ₁ is "ON", the dotted line position of the selector switch 13b is the left side, the output bi - connected to the arm current m side "ON", and the output bi - according to the beam current m The adjustment unit Ra is adjusted according to the detection value S ₂ , that is, the brightness of the display display screen, and the image quality adjustment circuit 7 a in the video chroma circuit 7 is adjusted. This makes it possible to adjust the screen according to the surrounding situation.
[0038]
When the ON / OFF signal S ₁ is “OFF”, the change-over switch 13b is “OFF” which is cut off from the position of the solid line on the right side of the figure and the output beam current m side, and connected to the user control side. to "oN", and the output bi - becomes independent of the detected value S ₂ according to the beam current m and the adjustment part Ra, the adjustment part Ra of the image quality adjusting circuit 7a is to be adjusted in a conventional user control .
[0039]
[Embodiment 4]
With reference to FIG. 4, still another embodiment of the high-definition display device according to the present invention will be described.
In FIG. 4, an adjustment unit Ra and a fixed unit Rb are provided for the user control for adjusting the image quality adjustment circuit 7a in the video / chroma processing circuit 7 in the high-definition display device. The adjustment range of the circuit 7a is limited. Moreover, the short-circuit switch 13c of the fixing portion Rb provided with ON / OFF signals S ₁ indicative of the overlap period, and is adapted to activate said shorting switch 13c.
[0040]
When the ON / OFF signal S ₁ is “ON”, the short-circuit switch 13 c is in the “OFF” position on the left dotted line in the figure, and the adjustment unit Ra and the fixing unit Rb are connected in series. Therefore, the adjustment range of the image quality adjustment circuit 7a is limited.
By doing so, there is no possibility that the image disappears due to the image quality adjustment.
[0041]
When the ON / OFF signal S ₁ is “OFF”, the short-circuit switch 13c is in the “ON” position on the right-hand side of the figure, the fixed portion Rb is short-circuited, and only the adjustment portion Ra is used for normal user control. The image quality adjustment circuit 7a in the video / chroma circuit 7 is adjusted.
[0042]
[Embodiment 5]
With reference to FIG. 5, still another embodiment of the high-definition display device according to the present invention will be described.
In FIG. 5, in the high-definition display device, a changeover switch 13d is provided for an adjustment unit Ra that adjusts an image quality adjustment circuit in the video / chroma processing circuit 7, and a fixed contact portion of the changeover switch 13d is provided for user control. One switching contact portion of the changeover switch 13d is connected to the adjusting portion Ra side, and the other switching contact portion is connected to the bias circuit 9a side of the output circuit 9 to one terminal.
[0043]
When the ON / OFF signal S ₁ indicating the superposition period of the changeover switch 13d is “ON”, the position becomes the right dotted line in the figure, and the operating point of the output device 9 is adjusted by adjusting the bias circuit 9a. The beam current m changes and the PI signal and the SI signal are adjusted as a whole image to be displayed. Therefore, the display of SI information is not lost by image quality adjustment, and the screen can be adjusted according to the surrounding situation.
[0044]
When the ON / OFF signal S ₁ is “OFF”, the position is indicated by a solid line on the right side of the figure, and the image quality adjustment circuit 7 a in the video chroma circuit 7 is adjusted by adjusting the adjustment unit Ra by normal user control. Will be adjusted.
Although not shown, there is no problem even if the self-holding mechanism is used by the ON / OFF signal S ₁ indicating the superposition period and the operating point of the output device 9 is adjusted by the ON / OFF signal S ₁ .
[0045]
【The invention's effect】
As described above in detail, according to the configuration of the present invention, when the PI signal and the SI signal for selecting the PI signal are superimposed, the SI signal is independent of the PI signal. In addition, it is possible to provide a high-precision display device and a high-precision reception method that can be controlled according to the surrounding conditions.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention.
FIG. 2 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention.
FIG. 3 is a schematic block diagram of a high-precision display device according to an embodiment of the present invention.
FIG. 4 is a schematic block diagram of a high-definition display device according to an embodiment of the present invention. FIG. 5 is a schematic block diagram of a high-definition display device according to an embodiment of the present invention.
FIG. 6 is a schematic block diagram of a conventional television receiver.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tuner 3 ... Digital demodulator 4 ... Digital decoder 7 ... Video chroma processing circuit 9 ... Output device 13 ... Changeover switch 13a ... Changeover switch 13b ... Changeover switch 13c ... Short circuit switch 13d ... Changeover switch 15 ... Bypass circuit 20 ... Antenna ra ... adjuster Rb ... fixing unit M ... microcomputer m ... beam current S ₁ ... PI signal and the ON / OFF signal indicating the superposition period of SI signal S ₂ ... beam current of the detection signal from the output device

Claims (4)

In a television receiver,
A tuner for receiving a digital television signal including an image signal and a service information signal;
A digital demodulator that demodulates an image signal and a service information signal received by the tuner;
A digital decoder for decoding the image signal demodulated by the digital demodulator and the service information signal;
A display unit capable of superimposing and displaying a first image corresponding to the decoded image signal and a second image corresponding to the decoded service information signal;
Detecting means for detecting a superposition period between the first image and the second image, and outputting a control signal indicating the superposition period;
A user adjustment circuit for adjusting the color intensity of the display image;
Preventing means for preventing user adjustment by the user adjustment circuit in the superposition period based on a control signal from the detection means;
A television receiver comprising:   2. The television receiver according to claim 1, wherein the digital decoder includes the detecting means. In a television receiver,
A tuner for receiving an image signal and a service information signal as a digital television signal;
A digital demodulator that demodulates an image signal and a service information signal received by the tuner;
A digital decoder for decoding the image signal demodulated by the digital demodulator and the service information signal;
A display unit capable of superimposing and displaying a first image corresponding to the decoded image signal and a second image corresponding to the decoded service information signal;
A user adjustment circuit for adjusting the color intensity of the display image;
When the first image and the second image are superimposed and displayed on the display unit, there are provided prevention means for preventing user adjustment by the user adjustment circuit with respect to the second image. A television receiver.   The television receiver according to claim 1, wherein the second image is an electronic program guide.

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