JPS5912832Y2 - Display circuit of digital tuner with clock - Google Patents

Description

[Detailed Description of the Invention] The present invention is designed so that one display circuit can be used both to display the operating status of the radio unit, such as the local status or DX status of the tuner, and to display whether or not the time can be adjusted. This invention relates to a display circuit for a digital tuner with a clock.

Recently, digital tuners have appeared that use a microcomputer in the control section and select channels digitally.

Such a digital tuner also has a clock function.

However, especially in car radios, the area of the front panel is small and the number of operation switches and display elements that can be mounted is limited, so the operation switch for the tuner and the operation switch for the clock are often used together, which prevents erroneous operation. Sometimes I don't know when to do something or when to do something.

The present invention eliminates such drawbacks, and particularly relates to a display circuit for a digital tuner with a clock that clearly displays the state in which the time can be adjusted, and will be described below with reference to the drawings.

1 is a control section consisting of a microcomputer,
The control unit 1 is in the first state, in which the first switch 4 switches between a first state in which the display 2 displays the reception frequency of the tuner 3 at that time and a second state in which the time is displayed in the display 2. When the second switch 5 is turned on when the
The tuner section 3 selects a channel by controlling the section 6.

7 is a third switch for DX/Local switching of the tuner section 3 that also serves as minute adjustment; 8 is a fourth switch that also serves as hour adjustment and selects channel selection sensitivity.
The switch 9 is a fifth switch for setting the time to the adjustable state or the memorizable state, and 10.11 is the first and second display circuit. Transistors 12.13 are turned on and off, causing light emitting diodes 14.15 to blink.

Reference numeral 16 denotes a third display circuit, which turns on a transistor 17 with a signal of level "1" generated from the MEI terminal of the control section 1 by turning on the fifth switch 9 when the control section 1 is in the first state, and emits light. diode 18
is lit.

At this time, the transistor 19 is turned on, and the signal generated when the fifth switch 9 is turned on is transmitted to the first and second display circuits 1.
It prevents it from being added to 0.11.

Reference numeral 20 denotes a first flip-flop controlled by the third switch 7, and its output turns on or off a transistor 21 to put the tuner section 3 in a local state or a DX state.

A second flip-flop 22 is controlled by the fourth switch 8, and by turning on and off a transistor 23, increases and decreases the amplification degree of the sensor amplifier 24 and changes the tuning sensitivity.

25 is an intermediate frequency amplifier, 26 is an audio amplifier, and 27 is a speaker.

Next, the operation of the present invention will be explained.

(1) When the control section 1 switches the first switch 4 so that the display 2 displays the reception frequency in the first state.

When the second switch 5 is turned on in this state, the counter of the control section 1 counts, changes the frequency division ratio of the programmable counter of the PLL section 6, changes the control voltage applied to the tuner section 3, and changes the control voltage applied to the tuner section 3. The tuning frequency and local oscillation frequency of the antenna circuit No. 3 are changed to select a different signal from that which has been received so far.

Further, when the fifth switch 9 is turned on, the transistor 28 is turned on and a signal is applied to the ME2 terminal of the control section 1, so that the control section 1 becomes in a memory-enabled state.

Therefore, pressing a preset button (not shown) presets the signal being received at that time.

At this time, since the MEI terminal becomes level "1", the transistor 17 is turned on, causing the light emitting diode 18 to emit light, thereby indicating the memory enabled state.

At the same time, transistor 19 is turned on, so the fifth
The signal caused by turning on switch 9 is not applied to transistor 12.13.

When the third switch 7 is turned on, the first flip-flop 20 is inverted, the Q terminal, which has been at level "0", is brought to level "1" and the transistor 21 is turned on.

Then, the tuner section 3 is switched from the Local state to the DX state.

At this time, the transistor 12 is turned on, and the light emitting diode 1
4 is emitted, so it can be seen at a glance that it is in the DX state.

Furthermore, when the fourth switch 8 is turned on, the second flip-flop 22 is inverted, the Q terminal becomes level "1", the transistor 23 is turned on, the amplification of the sensor amplifier 24 is increased, and a small signal is added to the intermediate frequency amplifier. The search stop signal can be obtained even when the search is stopped.

Therefore, if the search button is pressed in this state, the search can be stopped for all received signals.

(When the amplification degree of the sensor amplifier 24 is low, even if a small signal with a poor S/N ratio is applied to the intermediate frequency amplifier 25, the search stop signal will be activated. Therefore, even if such a small signal is received, the search will not be stopped. .

) This state is indicated by the transistor 13 turning on and the light emitting diode 15 emitting light.

(2) When the control section 1 switches the first switch 4 to the second state in which the time is displayed on the display 2.

To adjust the time in this state, the fifth switch 9 is turned on to make the transistor 29 operable.

By turning on the fifth switch 9, the transistors 12 and 13 are turned on and the light emitting diodes 14 and 15 are turned on.

Therefore, when the time is displayed on the display 2 and the light emitting diodes 14 and 15 are lit, it can be seen that the time can be adjusted. Therefore, if the third switch 7 is turned on in this state, the transistor 30 is turned on. is turned on and a signal is applied to the MIN terminal to perform minute adjustment.

Further, when the fourth switch 8 is turned on, the transistor 31 is turned on and a signal is applied to the HR terminal to perform time adjustment.

As described above, in the display circuit of the digital tuner with clock of the present invention, when the control section is in the first state in which the received frequency is displayed, the display circuit is made to blink only by the control switch that changes the operating state of the radio section. When the radio section is in the second state where the time is displayed, the display circuit is made to blink only by the changeover switch, so that the display circuit can be used to determine whether the tuner of the radio section is in the Local state or DX state, or whether the amplification level of the sensor amplifier is on. It is possible to display the operating state of at least one of the radio sections, ie, whether the radio section is in a large or small state, and to display whether or not the time can be adjusted.

[Brief explanation of drawings]

The figure is a display circuit diagram of a digital tuner with a clock according to the present invention. DESCRIPTION OF SYMBOLS 1... Control part, 2... Display unit, 3... Tuner part, 7... Third switch, 8... Fourth switch, 9... Fifth switch, 10... Third switch 1 display circuit,
11... Second display circuit, 16... Third display circuit.

Claims (1)

[Scope of utility model registration request] A control unit 1 exhibiting a first state in which a display unit 2 displays a received frequency and a second state in which a time is displayed, and when the control unit 1 is in the first state, it is in a memory enabled state, and when it is in the second state, it is in a memory enabled state. A changeover switch 9 for enabling time adjustment, and a switch 9 for switching the tuner 3 of the radio section to the Local state or DX state when the control section 1 is in the first state, or for switching the amplification degree of the sensor amplifier 24 to a large or small state. A control switch 7.8 for switching the operating state of at least one of the radio sections and a display circuit 10.11 are provided, and when the display circuit 10.11 is in the first state, only the control switch 7.8 is provided. The clock is characterized in that the operating state of the radio unit is displayed by blinking at the time, and when it is in the second state, it is caused to blink only by the changeover switch 9 to indicate whether or not the time can be adjusted. Display circuit for digital tuner.