FI89651B - Electronic knaeppningssvar Foer en folieknappsats i en mobile phone - Google Patents

Description

5 1 89651

Mobile phone membrane keypad electronic click response - Elektroniskt knäppningssvar för en folieknappsats i en mobilelefon

The invention relates to a method for providing a click response of a membrane keypad of a mobile telephone device according to the preamble of claim 1 and a corresponding circuit arrangement according to the preamble of claim 3.

In a mobile phone, especially its hand-held handset, i.e. the operating device, the aim is a lightweight structure and, on the other hand, the inexpensive structure required for mass production. In the case of a keyboard, a membrane keyboard which is known per se in terms of its operating principle and which is widely used is an advantageous solution. The membrane keyboard is thin and inexpensive, but it lacks the lack of clear tactile feedback.

20

A very clear and reliable operation is required of a mobile device, especially when used by a person driving a car. For example, when you press a key, you should get clear feedback that the press was successful. The simplest way to provide feedback is in the form of some sound, as is quite common in other types of keyboards.

When the membrane keyboard is pressed, there is no mechanical movement that could in itself produce the desired feedback sound. Attempts have been made in the past to solve this problem; by placing the bubble switch level firmly associated with it below the button level of the keyboard. The bubble switches produce a sound when the corresponding key is pressed. The disadvantage of this solution is the doubling of the structural thickness and also the price. In addition, the bubble plane is metallic and thus does not transmit the light used for the backing of the plastic keyboard.

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According to the present invention, an excitation pulse indicating the pressing of a key is applied in the circuit to an audio circuit in which the pulse produces an audible click. The circuit arrangement according to the invention essentially comprises a capacitance 5 in the conductor circuit arranged between the excitation pulse output of the keyboard logic indicating the keystroke and the input of an amplifier arranged in the audio circuit of the mobile telephone.

The circuit arrangement according to the invention utilizes circuit elements already present in the mobile telephone, between which, for example, a capacitor is connected. In this case, a click is heard when the key is pressed, which is heard and felt.

The invention will now be described with reference to the drawing, in which Figure 1 is a simplified schematic diagram of circuits related to the invention of a mobile telephone and Figure 2 is a diagram corresponding to Figure 1, in which the connection points of the keypad 20 are shown in slightly more detail.

In the method according to the invention, the excitation pulse P indicating the pressing of the keypad 1 is applied in the circuit C to the audio circuit 2, where the pulse produces an audible click (Fig. 1).

2 S

Figure 1 shows, by way of example, the parts of a mobile telephone which are essential to the invention and the circuit arrangement with which the audible click is produced. The membrane keypad 1 is associated with a switch matrix (switches S1-S20 in Fig. 30 2) in a manner known per se, from which a stimulus pulse P and a key identity are obtained when the key is pressed via logic circuits L to a microprocessor MC controlling mobile phone operation. At point A, logic L produces a pulse edge, 35 when the key is pressed, and another pulse edge when the key is released.

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The mobile telephone, on the other hand, comprises an audio circuit 2, the essential components of which are a speaker S and an amplifier V controlling it. At the input IN of the amplifier there is a point B.

According to the invention, a suitably sized capacitor C is connected between said points A and B, which conducts the pulse edges of the excitation pulse P from point A to point B. In this case, the audio circuit 2 produces an audible clicking sound when a button on the membrane keyboard 1 is pressed.

10

The solution according to the invention is cost-effective, because in addition to capacitor C, only a simple wire pull between points A and B is required to produce a click.

15

In the example shown, all said circuits are included in the handset of the mobile telephone. In this case, clicking in addition to the sound pulse preferably produces a vibration which is noticeable in the hand. Alternatively, it could be thought 20 that the audio circuit 2 is located separately from the membrane keyboard 1, e.g. in a fixed drive mounted in a car.

Claims (5)

A method for inducing a click response of a membrane keypad of a mobile telephone device, characterized in that an excitation pulse (P) indicating the pressing of the keypad (1) is applied in 5 circuits (A to B) to an audio circuit (2), where the pulse produces an audible click. A method according to claim 1, characterized in that said excitation pulse is generated from the keyboard logic (L) of the mobile device 10 and that the audible click is produced by a speaker (S) controlled by an amplifier (V) arranged in the audio circuit (2) of the mobile device. A circuit arrangement for providing a click response of a membrane keypad 15 of a mobile telephone device, characterized in that it essentially comprises a capacitance (C) in the conductor circuit (A-B) arranged in the excitation pulse output (A) of the keypad logic (L) for pressing the keypad (1) (2) between the inputs (B) of the 20 amplifiers (V) arranged. Circuit arrangement according to Claim 3, characterized in that the audio circuit comprises a loudspeaker (S) in the operating device of the mobile telephone device. 25 4 3965! Circuit arrangement according to Claim 3, characterized in that the audio circuit comprises a loudspeaker (S) in the handset of the mobile telephone device. 5 8 9 6 5 ί