JPH064991U - Function switching device for audio equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a function switching device having good operability regardless of the operating conditions at the time of switching. [Structure] When a large number of contacts of the function switching means are sequentially switched, if switching of one contact is within a fixed time, it is determined that switching is performed, the program source on the display is changed, and a fixed time is passed after the switching operation. When a lapse of time has passed, it is determined that the switching has been decided, the mute circuit is operated, and then a microcomputer control unit for reproducing the switched program source is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sound reproducing device equipped with a plurality of program sources including player devices such as a radio receiving device, a cassette tape, and a compact disc, and more specifically, for selectively switching the reproducing program sources such as the above radio and tape. Function switching device.

[0002]

[Prior art]

 Recently, various commercially available stereo playback devices are generally equipped with an AM / FM radio receiving device as well as a cassette player and a CD player, etc., and it is possible to selectively switch between a plurality of program source outputs for playback. Is possible. A function changeover switch is usually provided in such a reproducing apparatus, and a desired program source can be selected by operating this function changeover switch.

FIG. 3 shows an example of the function changeover switch. Normally, the function changeover switch is composed of a rotary switch or a slide switch, but the function changeover device 10 of FIG. 3 uses a rotary switch to select the operation source among plural source signals of CD, AM, FM and TAPE. The source signal at the position rotated by 12 is selected, and the reproduction signal is output to the speaker.

In general, such a function switching circuit also switches the power supply so as to supply power to the selected function, so that a transient current flows at the time of switching, and this transient current causes a high level in the reproduction signal. Levels of pulsed noise may occur. For this reason, conventionally, a noise prevention device has been considered in which the mute circuit is operated for a certain period of time from the start of function switching to prevent the reproduction signal including noise from being output. It should be noted that the CR time constant is usually used so that the mute circuit operates only for a fixed time.

[0005]

[Problems to be solved by the device]

 In the function switching device 10, the time constant T of the mute circuit for preventing noise during operation is set to an appropriate length in consideration of general switch operating conditions of the operator. However, the switch operation time varies depending on the operator, and if the constant mute time T and the switch operation time do not match, an operation problem occurs in the playback device.

For example, when the switch is switched from CD to TAPE in FIG. 3, three switching operations are performed via the AM and FM positions. When these three switching operations are faster than a certain time T, , The mute time continues after switching. In other words, the unnecessary silence continues. On the contrary, when the switching operation is extremely slow and one switching operation for switching one contact is slower than the predetermined time T, the sound of AM and FM radio is output momentarily for each switching. Such a momentary voice output is recognized as noise. The present invention has been made in view of the above circumstances, and an object of the present invention is to eliminate a problem in switch operation and to provide a high-quality function switching device.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, in the function switching device for audio equipment according to the present invention, a function switching means for selectively switching a desired program source from a plurality of program sources, and a voice signal temporarily after the operation of the function switching means. When the mute means for shutting off the switch and the function switching means are detected, the display of the mode display is changed to the display of the switched program source, and a certain time has elapsed after the operation of the switching means. Determines that the switching has been confirmed, activates the mute means, shuts off the program source before switching, which is continuously being reproduced, and reproduces the program source selected by switching after the mute is released from the mute means. And means.

[0008]

[Action]

 When the function selector switch is operated, the system microcomputer detects this. When switching a large number of contact points of a function switch composed of a rotary switch in sequence, if the switching of one contact is within a certain time, the system microcomputer will judge the switching, but after the switching is completed, the next operation is not performed. After a certain period of time, it is determined that the switching has been confirmed, and the process proceeds to the next step. When the function switching is detected, the mode indicator displays the switched program source, but the program source before switching is continuously reproduced at the speaker output. When switching is confirmed, the program source after switching is played after a temporary mute period.

[0009]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a reproducing apparatus according to the present invention. In the figure, 20 is an AM unit that receives an AM radio broadcast, 21 is an FM unit that receives an FM broadcast, and 22 is a reception antenna that receives the broadcast radio wave. Reference numeral 23 is a tape portion for reproducing a cassette tape, and 24 is a disc player for reproducing a compact disc, or a CD portion provided with a CD changer. The AM section 20 and the FM section 21 are program sources for receiving radio broadcasts and outputting audio signals, and the tape section 23 and the CD section 24 are for reproducing a recording medium on which music and the like are recorded to reproduce audio signals. Is the program source that outputs.

The operation of these program sources 20, 21, 23, 24 is controlled by the system microcomputer 35, and audio signals are output to the output lines a, b, c, d. Reference numeral 30 is a program source selection circuit for selectively switching the signals of the program source output lines a, b, c, d to take out a desired signal. This source selection circuit 30 uses a rotary switch having four switching contacts to connect the signals a, b, c, and d so that the source signals can be sequentially switched. Has become. Reference numeral 31 is a mute circuit for cutting off an audio signal. After the operation of the source selection circuit 30 is completed, this circuit is provided with a switch between the signal transmission line and the ground so that the audio signal is temporarily cut off, and the switch is closed for a certain period of time under the control of the microcomputer 35. Has been done. Reference numeral 32 is a control circuit for appropriately controlling the volume and sound quality, 33 is an audio amplifier circuit, and 34 is a speaker. Further, 36 is an operation unit, 37 and 38 are display drivers, and 39 and 40 are indicators. The first display 39 displays the operation mode such as the program source, and the second display 40 displays the radio reception frequency and the like.

Next, the operation of the above circuit will be described with reference to the flowchart of FIG. When the operator operates the source selection circuit 30 to switch the function, the system microcomputer 35 detects the function switching, that is, the operation of the source selection circuit 30 (S-1). When the microcomputer 35 detects the function switching, it sends a mode display signal to the display driver 37, and the new program source switched to the first display 39 is displayed in the mode. This mode display is updated to a new mode every time the source selection circuit 30 is sequentially switched (S-2).

Here, as a condition for the microcomputer 35 to judge the function switching, one switching operation for switching from one contact to the next contact of the source selection circuit 30 is performed within a fixed time, for example, within 0.5 seconds. In some cases, it is determined that the switching operation has been performed, and the display mode is updated to the new switched mode. However, when the switching is performed within 0.5 seconds, the audio signal output to the speaker 34 is not substantially switched, and the program source before switching is continuously reproduced. The source selection circuit 30 is controlled by the microcomputer 35 so that the source signal before switching bypasses the source selection circuit 30. After the function switching operation, the microcomputer 35 determines that the switching operation is finally finalized after a lapse of a fixed time, for example, 0.5 seconds, and performs the next operation (S-3).

The microcomputer 35 controls the mute circuit 31 to temporarily cut off the audio signal input to the volume sound quality control circuit 32. Therefore, the reproduction of the program source before the function switching, which is continuously reproduced, is stopped, and the speaker 34 temporarily becomes silent (S-4). Next, the microcomputer 35 operates the program source of the mode displayed on the display 39 (S-5). At the same time, the microcomputer 35 releases the silence state of the mute circuit 31 and sends the reproduction signal of the program source started in step S-5 to the volume sound quality control circuit 32 (S-6).

As a result, the function switching is operated in step 1, and any one of the program sources 20, 21, 23 and 24 is reproduced from the speaker 34, and the routine is ended. Then, the program source that was being played back is smoothly switched to the newly selected program source after a temporary mute time in step 4, and no sound is produced for a while after the function is switched. Also, the problem peculiar to the function switching device that noise is output at each switching is solved, and the operability of the playback device is improved.

[0015]

[Effect of device]

 As described above, according to the function switching device of the present invention, the function switching means for selectively switching the desired program source, the mute means for temporarily cutting off the audio signal after the function switching, After a certain period of time has passed since the function was switched, it is determined that the switching operation has been confirmed, the mute means is activated, and the control means for starting the reproduction of the program source after the switching is provided. To provide a high-quality function switching device that can prevent noise that occurs at each switch switching and unnecessary silence after switching regardless of switching conditions, improve operability and reliability of equipment, and provide a high-quality function switching device. You can

[Brief description of drawings]

FIG. 1 is a block diagram of an audio device according to the present invention.

FIG. 2 is a flow chart for explaining the operation of the device.

FIG. 3 is a diagram showing an example of a function switching device.

[Explanation of symbols]

 20, 21, 23, 24 Program source 30 Source selection circuit 31 Mute circuit 35 Control unit 39 Display

Claims (1)

[Scope of utility model registration request] 1. In an audio device having a plurality of program sources, a function switching means for selectively switching a desired program source from the plurality of program sources, and a sound signal is temporarily cut off after the operation of the function switching means. When the operation of the mute means and the function switching means is detected, the display of the mode display is changed to the display of the switched program source, and the switching is confirmed when a certain time has elapsed after the operation of the switching means. And a control means for activating the mute means, interrupting the program source before switching, which is continuously reproduced, and reproducing the program source selected for switching after the mute of the mute means is released. A function switching device for audio equipment.