JPS62110372A - Display circuit - Google Patents

Abstract

PURPOSE:To indicate the state of connection of external apparatus by the display circuit when inputting external apparatus by using a mode indicating circuit at the time of broadcast signal receiving for indicating the state of connection of external apparatus in common. CONSTITUTION:When a setting switch 10 is set to stereo side, a signal is given to the base of a switching transistor 9 of external input at the time of external input to ground the bases of transistors 5-8 and make them inactive state. A signal is given to the base of the transistor 5 at the time of stereo, and lights up a stereo display LED 1. Similarly, LED 2 - LED 4 for monoral display, main voice display and sub-voice display are lit up. Accordingly, all LED are put out by operation of the transistor 9. However, LED 1 is connected to the collector of the transistor 9 through the switch 10, and only LED 1 is displayed. When the switch 10 is set to monoral side, the display circuit is made to display LED 2 as in the case of setting stereo.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a display circuit for indicating the status of an external audio input terminal used in color television receivers and the like.

Conventional technology Traditionally, color television receivers, audio equipment, and VT
An external audio input terminal is provided for connection of R, etc. Hereinafter, a conventional external audio input terminal will be explained with reference to the drawings.

FIG. 2 shows the configuration of a conventional external audio input terminal. In Fig. 2, 21 is the right audio input terminal;
2 is a left audio input terminal, and 23 is a setting switch for switching between stereo and monaural.

In the external audio input terminal configured as described above, first, when inputting Nuteleo audio, the setting switch 23 is set to the stereo side, and the right terminal 21 and the left terminal 22 are not connected. Next, when inputting monaural audio, set the setting switch 2.
3 is the monaural side, and the right terminal 21 and left terminal 22 are connected. With this setting switch 23, it is possible to input each noural sound by simply connecting it to either the right terminal 21 or the left terminal 22, without having to provide separate terminals for stereo audio and monaural audio.

Problems to be Solved by the Invention However, with the above configuration, the only way to indicate the setting status to the user is through the display written on the setting switch. , it was not suitable when installed inside a door.

In view of the above problems, the present invention provides a display that can clearly indicate the connection state of external devices.

Means for Solving the Problems The display circuit of the present invention doubles as a mode display circuit when receiving a broadcast signal to display the connection status of an external device, and when an external device is input, the mode display circuit displays the connection status of the external device. is displayed.

According to the display circuit of the present invention, the state of the audio signal reception mode is displayed when receiving a broadcast signal, and the connection state of the external audio input terminal is displayed when an external audio input terminal is input.

This allows for clear display even when inputting from an external source.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows the circuit configuration of a display circuit in one embodiment of the present invention.

In Fig. 1, 1 is a stereo display light emitting diode (
LED), 2 is monaural display LED, 3 is main audio display L
ED, 4 is sub audio display LED, 5 is stereo display LED
A drive transistor, 6 is a monaural display LICD drive transistor, 7 is a main audio display LED drive transistor, 8 is a sub audio drive transistor,
These are similar to conventional reception mode display circuits. Furthermore, 9 is a switching transistor for external input, 1o is a stereo/monaural setting switch, 11 is a right audio input terminal, and 12 is a left audio input terminal.

The operation of the display circuit configured as described above will be explained below. First, when the setting switch 1Q is set to the stereo side, a signal is applied to the base of the external input switching transistor 9 at the time of external input, and it operates.
The bases of transistors 5, 6°7.877) are grounded, and transistors 6.6°7.8 are inoperative. Here, the transistor 5 is for driving the stereo display Ill:DI, and operates when a signal is applied to the base during stereo, and lights up the stereo display LED 1. Similarly, the monaural display LED 2, main audio display LED 3, and sub audio display LED 4 are also turned on by the respective drive transistors 6.7.8. Therefore, the operation of transistor 9 serves to erase all I4Ds. However, stereo display L
ΣD1 is connected to the collector of transistor 9 via setting switch 10.

Here, since the transistor 9 is conductive, only the stereo display LED 1 is displayed.

Here, the setting switch 10 has two interlocking circuits and two contact points.

Next, when the setting switch 1o is set to the monaural side, the right audio terminal 11 and the left audio terminal 12 are connected, and input is possible by connecting to either the right audio terminal 11 or the left audio terminal 12. At the same time, as in the case of stereo display, the display circuit is set to monaural Ll! :Display D2.

Note that when receiving a broadcast signal, no external input signal is input to the base of the transistor 9, and the drive transistors 5, 6, and 7.8 control the stereo, monaural, main audio, and sub audio LEDs 1.

Display 2.3.4. At this time, the stereo display and monaural display paths on the setting switch 10 side are open and do not work because the transistor 9 is not operating.

As described above, according to this embodiment, by using the display circuit when receiving a broadcast signal, the setting status can be displayed on the LICD even when inputting from an external device, and it is possible to clearly display the setting status in accordance with the equipment instruction manual. Can be displayed.

Effects of the Invention As described above, according to the present invention, the connection status of the external audio input terminal can be displayed using the display circuit in broadcast reception mode, and a clear display can be shown to the user. , its practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a display circuit in an embodiment of the present invention;
FIG. 2 is a circuit diagram of a conventional stereo/monaural switching device. 1... Stereo display LED, 2...
...Monaural display LED, 3...Main audio display L
ICD, 4... Sub-audio display LTID, 5
...Stereo display LED drive transistor, 6...Monaural display LED drive transistor, 7...Main audio display LED drive transistor, 8...Sub audio display LICD Drive transistor, 9... External input switching transistor, 11... Right input terminal, 12... Left input terminal. Name of agent: Patent attorney Toshio Nakao and one other person
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Claims (1)

[Claims] A display circuit comprising means for detecting a connection state at an external audio input terminal for connection with an external device provided in a television receiver, and means for displaying the connection state by a broadcast signal reception mode display circuit.