JPS631774B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tuner, and particularly to a channel selection device in a tuner.

With conventional tuner channel selection devices, the desired broadcasting station is selected by sequentially receiving broadcast waves in low or high order, and listening to the reception level or the received content while listening to the playback sound, unless the station is preset. An operation was being carried out to do so.

Therefore, with conventional channel selection devices, it is not possible to select a station without knowing in advance which broadcasting station has the strongest radio waves, and it takes a relatively long time to finally select the desired station. It was necessary.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a channel selection device that reduces the time required for a channel selection operation and facilitates the channel selection operation.

The channel selection device according to the present invention includes a display device that displays the received electric field strength of broadcast waves from each station all at once, and combines this display device with a predetermined operator such as a probe for specifying a channel selection position. This makes it possible to select stations.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a tuning device for an FM tuner according to the present invention, and a received signal is supplied to an input terminal IN. This received signal is transmitted to the front end section 1.
The signal is supplied to a high frequency amplifier 2 and mixed by a mixer 3 with a local oscillation frequency signal from a PLL type local oscillation circuit 4, for example. The output signal of the front end section 1 is supplied by the IF section 5 to the FM detector 6 as an IF signal containing only IF components. The output signal of the FM detector 6 is demodulated by a demodulator 7 such as a multiplexer and sent to an output terminal OUT. The parts explained above are the components of a normal FM tuner. The tuning device according to the present invention generates a logic "1" signal when the frequency deviation of the carrier component of the output signal of the S meter detector 8 and the FM detector 6, which output power according to the electric field strength of the IF output, is zero. It includes a zero volt switch 9. Level detector 10 generates a logic "1" signal when the output of S-meter detector 8 is above a predetermined level. The outputs of the zero volt switch 9 and the level detector 10 are both logically summed by an AND gate 11 and supplied to a controller 12. The output of the S meter detector 8 is converted into a digital quantity by an AD converter 13 and supplied to the controller 12 . The controller 12 starts in response to a trigger signal from a trigger signal generation circuit 14 that generates a trigger signal when the power is turned on, and sends a control signal to the local oscillation circuit 4 so that the tuning frequency of the front end section 1 changes sequentially. send. By sequentially changing the tuning frequency, an IF output corresponding to the broadcast waves from different stations is obtained, and each time the tuning to the station frequency is achieved, a logic "1" is output from the zero volt switch 9 and the level detector 10.
When the signal is output, a station presence indicating signal of logic "1" signal is output from the AND gate 11 to the controller 12.
is supplied to The controller 12 stores in the memory 15 a digital signal representing the received electric field strength from the A-D converter 13 when receiving this station presence indicating signal. On the other hand, the station position indication signal is supplied to a muting control circuit 16, and the muting control circuit 16 performs muting so that no output signal is output from the demodulator 7 when receiving the station presence indication signal.

The controller 12 changes the local oscillation frequency so that the tuning frequency of the front end section 1 covers the entire FM broadcast wave band, and then changes the local oscillation frequency to the driver 1.
The information stored in the memory 15 is transferred to 7. The driver 17 preferably drives a two-dimensional pattern display 18 according to the transferred storage information, and the display 18 displays the received electric field strength of each station all at once. The display pattern of the display 18 may be, for example, as shown in FIG.

The operator can select a station in one go by bringing the operator 19, such as a light pen, close to the spatial position assigned to the desired station on the display surface. Information on the proximity position of the operator 19 is fed back to the driver 17 via the lead 20, and further fed back from the driver 17 to the controller 12, and the controller 12 determines the local oscillation frequency based on this feedback information and completes the channel selection operation.

Although the above embodiment is a channel selection device of the present invention for an FM tuner, a similar channel selection device can be configured for an AM tuner as well. In this case, zero volt switch 9 and AND gate 11
It is also possible to omit this and use only the output of the level detector 10 as the station presence indicating signal.

As explained above, in the tuner selection device of the present invention, when turning on the power to the tuner, etc.
Each station's signal is received in sequence, and the received field strength of each station is temporarily stored in memory via an A/D converter, and then these are displayed all at once on a two-dimensional display as receivable stations and their reception level information. When the operator touches the display with an operator such as a light pen, the station corresponding to the touch position is automatically selected, so the operator can play the S/N etc. This is extremely convenient because it allows you to compare and recognize the reception level of each station in advance, which is closely related to sound quality, and then select the station with the best playback quality. can be continued as is or redisplayed as necessary, and since the search for each station is not repeated and displayed as in the past, the reproduction of the audio is not interrupted. Further, since it is possible to select a channel based on the input using the operator and the stored information, it is possible to select a channel in a short time without the need for a separate search, which is preferable.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG.
The figure is a schematic diagram showing a display mode of the channel selection device according to the present invention. Explanation of symbols of main parts, 1...Front end section, 5...IF section, 6...FM detector, 7...Demodulator, 8...S meter detector, 9...Zero volt switch, 10... Level detector, 12...controller, 13...A-D converter, 14...trigger signal generation circuit.

Claims (1)

[Claims] 1. Local oscillation frequency variable means for sequentially changing the local oscillation frequency of the tuner at least when the tuner is powered on; and IF level detection means for generating an IF level signal representing the IF output level of the tuner. and a station position detection means for detecting the presence of a station carrier wave using an IF output and generating a station presence signal;
storage means for storing the electric field strength of received radio waves for each station based on the IF level when the station presence signal is generated; and display means for simultaneously displaying the stored electric field strength of each station at each spatial position assigned to each station. What is claimed is: 1. A tuner channel selection device, characterized in that a channel selection operation is automatically performed by bringing a predetermined operator close to a spatial position of a station to be selected on a display means. 2. The display means includes a display device that displays a two-dimensional pattern, and drives the display device so that the horizontal axis represents the station position and the vertical axis represents the received wave electric field strength according to the storage contents of the storage means. A tuner channel selection device according to claim 1, comprising a driver.