JPS62224128A - Control equipment for on-vehicle acoustic equipment - Google Patents

Abstract

PURPOSE:To attain the effect of burglar proof as a result by utilizing a microcomputer built in an acoustic equipment so as to generate a random data and operating the acoustic equipment when the random data and key input information have a prescribed relation. CONSTITUTION:When two prescribed keys 'A', 'E' of a key group 5 are operated simultaneously, a three-digit random data is generated from a random data generating means 11, and when the prescribed keys 'A', 'E' of the key group 5 are operated again, a random data (e.g., '185') generated just before the stop is displayed on a display device 6. In operating a key of the key group 4, a number (e.g., '2') corresponding to the key is displayed on the least significant digit of the display device 6. Whether or not the even/odd number being the result of the addition of the most significant digit number '1' and the least significant digit number '5' of the number '185' displayed is coincident with the even/odd number of the number is discriminated by an operation means 12, and when they are coincident, a coincidence signal is fed to a power switching means 13 to close the power supply circuit 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device for in-vehicle audio equipment installed in an automobile.

BACKGROUND OF THE INVENTION Various proposals have been made to prevent theft of in-vehicle audio equipment. For example, a device has been proposed that issues an alarm when someone illegally enters a vehicle. However, this type of device is not effective in preventing theft because the in-vehicle audio device can be used as an audio device if it is taken out of the vehicle.

For this reason, we have recently made modifications to the in-vehicle audio equipment itself.
2. Description of the Related Art Devices have been developed that prevent in-vehicle audio equipment from operating unless a specific operation is performed, resulting in a theft prevention effect. FIG. 3 shows an example of this type of device. In FIG. 3, 17 is a radio receiver with a built-in microcomputer, and various operation keys (for example, keys for AM/FM switching, keys for automatic channel selection, etc.), 18 are microcomputer keys, and 19 are keys for controlling reception frequencies, etc. The display device 20 is a non-volatile memory, and a specific code number is stored in the non-volatile memory 20.

In the above conventional example, when operating a radio receiver,
A predetermined code number was input using the operation key 17, and reception was possible only when the code number input using the operation key 17 and the code number stored in the non-volatile memo 1J20 matched. .

Problems to be Solved by the Invention However, in the above conventional example, the expensive non-volatile memory 20 (or volatile memory and memory backup power supply)
In addition to requiring the user to memorize a specific code number without error.

The present invention eliminates the above-mentioned drawbacks of the prior art and provides a device that does not require additional non-volatile memory and does not require storing specific code numbers.

Means for Solving the Problems In order to achieve the above object, the present invention generates random data using a microcomputer built into an audio device, and creates a predetermined relationship between this random data and key input information. This enables the audio equipment to operate when the

Function The present invention has the above-described configuration, and the audio equipment becomes operable only when information in a predetermined relationship is entered by keying into the random data displayed on the display, and even if the audio equipment is stolen, However, since the audio equipment cannot be operated substantially, the anti-theft effect can be obtained as a result.

EXAMPLE An example of the present invention will be described below. In FIG. 1, 1 is a radio receiver, and 2 is a power supply circuit. This power supply circuit 2 supplies or cuts off the voltage of a battery 3 to the radio receiver. Numeral 4 is a group of keys for preset channel selection provided in the radio receiver 1, and five stations can be preset in advance. 5 is a group of keys provided on the radio receiver 1 (for example, I'M, AM switching keys, automatic channel selection keys, etc.); 6 is a display that digitally displays the reception frequency; 7 is the display 6; This is the display drive circuit that drives the . 8 is the central processing unit (CPU), random access memory (RAM), read-only memory (I
It is a microcomputer consisting of LOM), Ilo, etc.

Next, the functions of the microcomputer 8 will be explained. Reference numeral 9 indicates key detection means for detecting that two predetermined keys (for example, keys rAJ and "E") of the key group 5 are pressed at the same time, and reference numeral 10 indicates a key group "1" to "1" for preset channel selection.
This is a key detection means for detecting which key among "5" has been pressed, and outputs a signal according to the pressed key. 1
1 is a random data generating means, and this random data generating means 11 generates two predetermined keys r from the above key group 5.
It operates according to the signal generated by the key detection means 9 when AJ and [J are pressed, and generates 3-digit random data. The three-digit random data generated by the random data generating means 11 is applied to the display drive circuit 7, and the random data is displayed on the top three digits of the display 6 which displays four-digit numbers as shown in FIG. 2A. . After the random data generation means 11 operates, predetermined two keys rA of the key group 5 are activated again.
J and 1'-1 (When J is pressed at the same time, the random data generation means 11 stops, and the display 6 displays the top 3 random data generated when the random data generation means 11 stopped.
Display the digits (for example, as shown in Figure 2A, the top three digits are
185J). The random data generating means 1
Random data generated in 1 (e.g. "l 85 J")
is input to the calculation means 12.

This calculating means 12 sends a signal corresponding to the number pressed in the key group 4 to the display driving circuit 7, and also sends the random data "185" sent from the random data generating means 11.
”, the most significant digit “1” and the least significant digit “5”
” and determine whether the addition result “1” + “5” = 6 is an even or odd number (in this example, it is determined to be an even number), and then whether the pressed key in key group 4 is an even or odd number. If both match, a match signal is output to the power switching means 13. In this example, the addition result of the most significant digit and the least significant digit of the random data is an even number, so when the key "2" or "4" of the key group 4 is pressed, the calculation means 12 A coincidence signal is output to the switching means 13. In the case of this example, odd-numbered keys "1", "3",
If "5" is pressed, no matching signal is output from the calculation means 12, and a retry is possible. 14 is a counting means for counting the number of trials of the above operation, and this counting means 14 outputs an output when the number of trials reaches a predetermined number (for example, 3 times).
The output "I-1" of this counting means 14 is applied to the power switching means 13, and makes this power switching means 13 inoperable. 15 is a power supply voltage detection means; The power supply voltage detection means 15 starts its operation from the "H" output of the counting means 14, and when the power supply voltage once reaches the "OII level" and then reaches the II14# level again, it outputs it to the power supply circuit 2 and changes the power supply voltage. is applied to the radio receiver 1. Reference numeral 16 denotes a switch connected between the power supply voltage detection means 15 and the power supply circuit 2, and this switch 16 is attached to a location on the radio receiver 1 out of sight.

Next, the operation of the above embodiment will be explained.

When the switch 16 is OFF, the voltage of the battery 3 is applied to the radio receiver 1 via the power supply circuit 2, and by operating the power switch (not shown) of the radio receiver 1, the radio receiver 1 is turned off. l can be operated.

When the switch 16 is ON, voltage cannot be supplied to the radio receiver 1 unless a predetermined key operation is performed. Next, its operation will be explained.

First, when two predetermined keys "A" and "E" of the key group 5 are operated at the same time, the random data generating means 11 and 93
Random data of digits is generated, and this random data is sequentially displayed on the top three digits of the display 6. Next, again key group 5
When predetermined keys rAJ and rEJ are operated, the operation of the random data generating means 11 is stopped, and the random data (for example, 1-185J) generated immediately before the stop is displayed on the display 6 (FIG. 2A). Here, if you operate one key in key group 4, the number corresponding to this key (for example, "2") will be displayed.
) is displayed on the lowest digit of the display 6 (FIG. 2B).

The calculation means determines whether the even/odd number of this number matches the even/odd number obtained by adding the highest number "1" and the lowest number "5" of the displayed number "185". 12, and if they match, a match signal is supplied to the power switching means 13. When the matching signal is supplied to the power switching means 13, a signal is supplied to the power supply circuit 2, which closes, and voltage is supplied from the battery 3 to the radio receiver 1, making the radio receiver ready for reception. .

On the other hand, when l'-185J is displayed in the upper three digits of the display 6, when "1" (odd number) in the key group 4 is operated, the calculation means 12 detects a coincidence between an even number and an odd number. Therefore, no matching signal is output to the power switching means 13, and the counting circuit 14 counts the number of trials as 1. Here, the same operation as above is performed again. In this trial, if the even numbers and odd numbers match in the calculation means 12, a match signal is output, the power supply circuit 2 becomes conductive 9, and the radio receiver 1 becomes ready for reception. If no match between even and odd numbers is detected in the second trial, the counting circuit 14 increases the number of trials to 2.
Count. Subsequently, a third trial is made, and if no match between even and odd numbers is detected, the counting circuit 14 counts the number of trials (3), outputs "H'", and disables the power switching means 13. The ゛I-1'' output of the counting circuit 14 is also applied to the power supply voltage detection means 15, and this power supply voltage detection means 15 is brought into operation.

This power supply voltage detection means 15 outputs an initialization signal when the power supply voltage once detects the "0" level and then detects the power supply voltage again (specifically, when the battery 3 is removed and reconnected). At the same time, the power supply circuit 2 is made conductive.

In the above embodiment, the number of keys operated in the key group 4 is an even or odd number that is the sum of the number of the most significant digits and the number of the least significant digits of the random data generated by the random data generating means 11. The power supply circuit 2 is controlled depending on whether the even numbers or odd numbers of All you have to do is do it. Further, in the above embodiment, power is supplied only after a predetermined operation is performed, but the power supply circuit is not limited to control of the power supply circuit.
It is sufficient to make the audio equipment inoperable unless a predetermined operation is performed.

Effects of the Invention According to the present invention, there is no need to add expensive memory or circuits such as non-volatile memory, and there is no need for the user to memorize his or her own code number, resulting in an anti-theft effect. I can do it.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control device for in-vehicle audio equipment according to an embodiment of the present invention, FIGS. 2A and B are diagrams showing examples of displays on the display of the same device, and FIG. 3 is a block diagram of a conventional example. be. ■... Radio receiver, 2... Power supply circuit, 3... Battery, 4.5... Key group, 6... Display, 7...
Display drive circuit, 8... Microcomputer, 9.1
0... Key detection means, 11... Random data generation means, 12... Calculation means, 13... Power supply switching means, 14... Counting means, 15... Power supply voltage detection means, 16. ··switch.

Claims (1)

[Claims] Random data generation means for generating random data;
a display for displaying random data output from the random data generating means; a calculating means for determining whether or not predetermined key input information and the random data have a specific relationship; A control device for vehicle-mounted audio equipment, comprising audio equipment control means that enables the vehicle-mounted audio equipment to operate when it is determined that input information and the random data have a specific relationship.