HK1017961B - A method and arrangement relating to mobile telephone terminals - Google Patents

Description

Method and apparatus relating to mobile telephone terminal

Technical Field

The present invention relates to mobile radio terminals and more particularly to so-called terminal keypad protection.

Description of the prior art

The complexity of modern mobile radiotelephone devices, such as mobile telephones, is increasing. It is possible for a user of a mobile phone to initiate a function by pressing a key on his/her keyboard and thereby initiate an extensive communication with another receiver. As a result of the progressive development towards smaller terminals, it is possible to place the terminal in the pocket of the user, with the result that there is a risk of one or more keys being unintentionally pressed on the mobile telephone. The risk of such an event also increases during the time the phone is started to operate. This may result in the establishment of a call connection, for example. In the worst case, the call will not be released until the owner of the terminal knows that the terminal is opened. Mobile phone calls are expensive and mobile phones have limited battery capacity. A person who is somehow disturbed by an unwanted telephone call may be irritated by the call, which the owner of the terminal may consider unpleasant, unnecessary and embarrassing. Therefore, it is necessary to prevent undesired and unintentional pressing of keys of the terminal keypad. Several methods and apparatus for preventing inadvertent pressing of keys on a keypad of a mobile wireless communications device, such as a mobile telephone, are known in the art.

EP-a1-0346747 teaches the use of a hinged cover under which the cover acts to protect the keypad when the mobile telephone is not in use. When the mobile phone is to be used, the cover is lifted up, exposing the keypad. The cover (or may also be referred to as a housing) is secured by means of a spring or some other type of latch or clamping device. The lid, hinge and latch are made of a plastic material. Therefore, the hinge and latch arrangement tend to age quickly, which releases the cover from its closed position, thereby leaving the keyboard unprotected. When the hinge or latch mechanism is complex, it can be expensive to repair. Also, the cover or housing may become detached from the phone for reasons other than long-term use. For example, the cover may loosen due to careless handling or due to damage caused by the phone accidentally falling onto a hard floor.

In another known cover mounting variation, the cover or lid may cover the keyboard forward or backward. It is then the fact that this device comprises an additional release element which can be released in some way from the phone. Moreover, mounting the cover or lid on the terminal involves additional manufacturing procedures, which increase the cost of manufacturing the terminal. The operation of a mobile phone equipped with a keypad protection cover, or shutter is further complicated by requiring the user to manually open and close the cover.

The mechanical keypad protector described above prevents inadvertent depression of the keys because the keys cannot be actually manipulated while the keypad is covered.

The problem of unintentionally pressing a key of a terminal keypad can be solved by locking the keypad unit so that no signal reaches the data processing unit even when some keys are activated, or so that no signal is generated even when one key is pressed. This can be solved by a switching device which is activated by means of a separate locking key. The keyboard unit is locked in one position of the switch and released in another position of the switch. However, one disadvantage of this solution is that the locking key may also be unintentionally activated to cause the switch to shift from the locked position to the released position. This can occur when the terminal is placed in a pocket or pocket between loosely carried items. This solution also complicates the operation of the mobile station by the user.

The user also wants to have the smallest possible number of keys on his/her terminal keypad. Fewer keys are also beneficial to manufacturers because more keys require a lot of space. Both manufacturers and users desire mobile phones that are small and easy to operate.

All of the above-described keyboard locking devices are basically mechanical devices. However, electronic terminal locking devices are also known in the art. Such A device is known, for example, from US-A-5212810. The purpose of this known automatic telephone locking facility is to prevent illegal use of the telephone. The phone will be automatically locked when a predetermined time interval has been exceeded after the phone has been turned on and activated. This prevents illegal use of the phone.

US-A-4,670,747 teaches A mobile telephone provided with an alphanumeric keypad and function keys and A display. Menu icons are provided on the alphanumeric display surface. The iconic symbols are selected by sequentially stepping the cursor over the desired menu icons. The selection of the icon is realized by a menu key. The icon is launched with a step key. If the user wishes to lock the keyboard, he/she steps the cursor onto the lock-icon by means of the menu key and presses the step key once. The keyboard will then be locked until the user presses the step key again. The locking process may be considered to have menu support because the process is a function stored in an icon on the display screen. The process is manual.

US-A-5,241,583 teaches A similar menu-based function selection procedure. However, the locking of the keypad is different from the locking procedure just described. In the latter case, the keyboard may be locked or unlocked by pressing two separate keys in a particular sequence. This key press combination is only used when locking or unlocking the keyboard and will not be used during other uses of the keyboard. Furthermore, the keys involved are preferably located as far apart from each other as possible. This reduces the risk of inadvertently unlocking the keyboard, unlike the former case, where only one key needs to be pressed in order to unlock the keyboard. It can be seen that pressing two widely separated keys in a particular sequence has less chance of occurring than pressing only one key. The keyboard is manually locked and cannot be supported using menus. Alternatively, a time limit may be inserted between the pressing of two keys in the locking procedure. This means that in order to unlock the keyboard, two keys in the locking program must be pressed within a given time interval.

Summary of The Invention

The present invention relates to the problem of preventing the keypad of a mobile radio terminal from being inadvertently pressed. As seen in the description of the prior art, various attempts have been made to solve this problem.

The problem includes how to implement activation and automatic deactivation of the keypad in a mobile radio terminal.

Another problem is how such enabling and disabling can be implemented in an easy way by the end user.

It is therefore another object of the present invention to prevent undesirable results when some keys on the keypad of a mobile radio terminal are inadvertently pressed.

It is a further object of the invention to simplify handling of a terminal when said terminal is in use and to simplify such handling before leaving the terminal in standby mode.

It is a further object of the invention to enable the phone to be kept in a standby mode in at least the same way as the security that is available with previously known keypad protectors, such as protective covers, shutters, or separate additional keys mounted on the front of the keypad, or separate additional keys used to activate and deactivate the keypad.

It is another object of the present invention to provide a technical solution to the problems encountered in other technical fields that use keypads and are suitable for mobile wireless communications and the problems and conditions thereof.

It is a further object of the invention to provide a technical solution that does not employ additional keys that require additional space and increase manufacturing costs.

These objects are achieved by means of the method according to the invention and the device according to the invention. Roughly speaking, the solutions to these problems are: automatic disabling of the keyboard is initiated upon expiration of a given time interval following the last key press.

According to this solution, a time parameter is set to zero each time a key is pressed, and a time measurement process using the time parameter is restarted, after which the time parameter is compared with a predetermined threshold value.

More particularly, the invention relates to the activation and automatic deactivation of keys in a keypad of a mobile telephone terminal, the terminal further comprising a display and means for detecting the pressing of said keys. A time parameter representing the time elapsed since the last depression of an arbitrary key is set to zero by a device suitable for this purpose and the value of the time parameter is counted after the zero setting of the time parameter. The time parameter is compared with a threshold value (Tlock) and the disabling of the keys of the keypad is automatically started immediately after the time parameter has exceeded the threshold value (Tlock). At least one suitably selected key is kept active to activate the keypad during the time that the keypad is in the disabled mode and the terminal is set to its standby mode.

The benefit derived from the solution to this problem is that the mobile telephone terminal is easy to handle and save by the user. The security of the mobile telephone terminal is maintained at least as reliably as the other known solutions described herein, however the way in which the terminal is kept secure is much simpler than in the described examples. The terminal can also be made in a small size because no space-consuming additional equipment in the form of a cover, a housing or a separate locking key is required. This also enables its manufacture to be kept at low cost. The invention also provides a solution that is well suited for mobile radio communication, especially when the terminal has a keyboard inhibit function that can only be activated manually.

The invention will now be described in more detail with reference to preferred exemplary embodiments thereof, and also with reference to the accompanying drawings.

Brief description of the drawings

Fig. 1a is a schematic front view of a mobile phone.

Fig. 1b is a block diagram showing an apparatus included in a mobile phone according to the present invention.

Fig. 2 is a schematic flow chart diagram showing the method of the present invention for enabling and automatically disabling a mobile phone keypad.

Description of The Preferred Embodiment

Fig. 1a is a schematic front view of a mobile phone 2. The mobile telephone comprises a display 4 on which the called telephone number, the received signal strength, the battery charge, and different types of menu functions are displayed. The mobile phone has a keypad 6 comprising function keys 8-14, a right key 8 and a left key 10, an affirmative key 12 and a negative key 14, and letter keys 16. The user of the mobile phone can activate different functions by means of function keys and a menu control and processing system. The user can step between different menus of the menu system by means of the right and left keys. When using the menu function, the ok and no keys can be used to answer questions displayed on the display screen. Thus, the ok key and the no key have several functions depending on the condition in which they are pressed. For example, they may be used to establish or release a telephone call connection. Terminals of this type may in some cases already be equipped with a menu support inhibiting function and means suitable for this. This type of disabling is manually initiated by the user.

Fig. 1b is a block diagram showing an apparatus included in a mobile phone according to the present invention. The mobile phone comprises a control unit 20 for controlling the method according to the invention. The control unit comprises a microprocessor with associated connected circuitry. The control unit controls, among other control functions, the scanning of the keyboard unit 22, the presentation of menus on the display screen through the medium of the control circuit 26, and the storage and reading of data in the various memories 28 and 30. These memories may be of the RAM, ROM, EEPROM, etc. type. The control unit also communicates with other parts of the mobile phone, for example with a wireless communication unit 32, which may also be microprocessor controlled. The mobile phone also comprises other means and functional units, although these are not shown in the figure, since they are not relevant for the description of the invention.

The control unit is connected to a timer 34 which comprises a counter 36 whose function is to count the time parameter t, and a comparator 42. The time parameter t may be started with a start signal and reset to zero with a reset signal from the control unit.

The control unit is connected to a keyboard unit comprising a keyboard 38 and means 40 for detecting the pressing of a key. The key depression detecting means registers the start signal Y0 and applies the signal to the control unit every time a key is depressed, regardless of the characteristics of the key. In response to the activation signal Y2, the control unit first transmits a reset signal Y1 to the counter, thereby setting the time parameter t to zero, and after that transmits an activation signal Y2 which starts counting the time parameter t, which is counted after each key press, until a new key press is logged in. The value of the time parameter t is periodically read out and stored in a comparator 42, in which a threshold value Tlock is also stored. This time value corresponds to the longest time the keyboard is active after the last key press.

The comparator 42 reads the time parameter t, compares the threshold value Tlock, and determines whether the time parameter value t exceeds the threshold value Tlock, i.e., the comparator checks whether t > Tlock has occurred. When this condition is satisfied, the comparator applies the alarm signal Y3 to the control unit 20, and the control unit 20 transmits a disable signal Y3 to the keyboard unit 22. This unit immediately disables all keys except one, which remains activated, to enable the user to re-activate the rest of the keyboard.

By "disabled" is generally meant that when a key is pressed, the control unit will no longer register any signals or information from the key that has been disabled to the relevant circuitry. The remaining circuitry of the mobile phone is not affected. Therefore, this disabling process will not be confused with known locking processes. On the other hand, a terminal equipped with a menu-supported manual disabling function and including a manual keypad disabling device suitable for the purpose can be equipped with an automatic function without a comprehensive structural modification. These disabling means may then be incorporated in the keyboard unit.

The control unit also transmits a reset signal to the counter which causes the time parameter value to be set to zero. The control unit also transmits a key-lock signal Y5 to the display control circuit 26 which causes the word "key-lock" to be displayed on the display screen, thereby informing the mobile station user that: the keyboard is disabled. The control unit also transmits a standby signal to the wireless communication unit 32 which places the wireless communication unit in a standby mode. If the wireless communication unit is not already in the standby mode, the unit is switched to this mode after receiving signal Y6.

When the keyboard is in the disabled state, the control unit is in a standby mode. In this mode, the control unit monitors and detects when a signal from the keyboard unit or the wireless communication unit is registered. For example, an activation signal is transmitted to the keyboard unit when one of the following events occurs:

-actuating a single working key (left or right).

-the wireless communication unit receives a new call.

-the battery needs to be charged.

When a call is received, the wireless communication unit transmits a call signal Y7 to the control unit, which in turn transmits an activation signal Y8 to the keyboard unit 22, in response to which the keyboard unit 22 activates all keys.

When the control unit is in its standby mode, the keypad is disabled and the wireless communication unit is in its standby mode and displays a standby menu and the word "key-lock" on the display. When it is desired to activate the keyboard, the user presses a unique activation key (8 or 10). The device for detecting the depression of a key in the keyboard unit transmits the alarm signal Y9 to the control unit, which in turn transmits the start signal Y2 to the counter 26, the menu switching signal Y10 to the display control circuit 26, and the start signal Y8 to the keyboard unit. Since the display screen shows "key-lock" in standby mode, the menu switching signal Y10 will cause the menu to switch to the "key-lock" menu, in which the problem is shown: "unlocked? ". As mentioned before, the mobile phone is equipped with keys for responding to questions posed on the menu. Each question is answered in the affirmative or negative by an affirmative key or a negative key, respectively.

Thus, if the first key pressed is unintentional, the affirmative or negative key will be pressed again.

If the affirmative key is pressed, the affirmative signal Y11 is transmitted to the control unit, which in turn transmits a start signal Y8 to the keyboard unit, a reset signal Y12 to the counter 26, and a menu switching signal Y10 to the display control circuit 26. The wireless communication unit is in standby mode and therefore displays a standby menu, however without the word "key lock". The keyboard is now activated and the control unit returns to its initial mode.

If the negative key is pressed, a negative signal Y13 is transmitted to the control unit, which in turn transmits a disable signal Y4 to the keyboard unit, a reset signal Y12 to the counter, and a menu switching signal Y10 to the display control circuit. The wireless communication unit is in standby mode and therefore displays a standby menu and displays the word "key-lock". The keyboard is now disabled again and the control unit is in a standby mode to activate the keyboard.

On the other hand, if the only actuated key is inadvertently pressed, it is highly likely that the time parameter t value will exceed the threshold value Tlock. Since the terminal is menu based, the control unit will only accept answers to the menu questions and will therefore not accept other signals than "positive" or "negative". In fact, during the short time Tlock when the keyboard is activated, only the positive or negative key will be activated. If any of these keys is inadvertently pressed during the time that it is activated, pressing the negative key will cause the terminal to be disabled, while pressing the positive key will only cause the keyboard to be re-activated for a time interval corresponding to Tlock. In this latter case, it is highly likely that inadvertent pressing of one key again will not occur.

The threshold value Tlock will preferably be chosen not to put the user in an urgent state between the times of pressing the keys due to the short Tlock time. Tlock, on the other hand, should not be selected to cause a high probability that a key is inadvertently pressed. The longer the keyboard is actuated, the higher the probability of an inadvertent key press. The value of Tlock is preferably in the range of 15-60 seconds, although shorter or longer time intervals are also contemplated.

The control unit will maintain the inhibit procedure in the initial mode until the terminal radio communication unit gives a full clear signal. If a call comes, the wireless communication section transmits a call signal to the control unit. The control unit will then immediately interrupt the inhibit process (if this inhibit process is in progress) and place the process in its start mode and wait for a full clear signal. When the disabling process is interrupted, a reset signal is automatically sent to the counter.

Fig. 2 is a schematic flow chart diagram showing the method of the present invention for enabling and automatically disabling a mobile phone keypad.

When the method is started, the control unit is in a start mode. The control unit detects: there is no ongoing call and the keypad is activated. The fulfilment of the start condition enables the control unit to initiate a disabling procedure, which will now be described in more detail.

At step 200, the time parameter t is set to zero, and at a next step 202, counting of the time parameter t is initiated. At step 204, a check is performed to determine if a key press is logged in. If the answer is negative, a test is carried out in step 206 to determine whether the time parameter t is greater than the threshold value Tlock. If the answer is negative, a check is again made to determine if a key press is logged in step 204.

If the response to the test at step 204 is positive, the time parameter t is set to zero at step 200 and the process is reinitiated.

When the response to the test at step 206 is positive, i.e. the time parameter t is greater than the threshold value Tlock, then the disabling of the keyboard is initiated at step 208.

When the keypad is disabled, the time parameter t is set to zero and the mobile phone is automatically set to standby mode if the user has not done it manually.

Due to this disabling, the keylock memory is displayed on the mobile phone display screen at step 210. A check is performed at step 212 to determine if the start key has been pressed. If the answer is negative, a test is carried out at step 214 to determine if an incoming call is detected. If the answer is negative, a test is carried out at step 216 to determine if a battery change has occurred. If the answer is negative, the test is repeated at step 212. These verification procedures 212-216 are carried out until one of the verification procedures produces a positive response.

When the response to the test carried out at step 214 or at step 216 is positive, the keyboard is activated at step 218. This enables the mobile telephone, for example, to be used in a conventional manner for receiving incoming calls.

When the response to the test carried out at step 212 is positive, a count of the zeroed time parameter t is initiated at step 220. A menu "unlock? ", which results in the actuation of a positive or negative key at step 224. A check is then performed at step 226 to determine if the time parameter t is greater than the threshold value Tlock. If the answer is negative, then a check is made at step 228 as to whether the negative key has been pressed. If the answer is negative, then it is checked in step 230 if the ok key has been pressed. If the answer is negative, the test of step 226 is repeated to determine whether the time parameter t is greater than the threshold value Tlock. When the answer to the test at step 226 is affirmative, i.e. when the time parameter t is greater than the threshold value Tlock, the disabling of the keyboard is re-initiated at step 208. The disabling of the keyboard at step 208 is also initiated when an affirmative answer is given at step 228, i.e. when the negative key is pressed.

If the answer to step 230 is positive, keypad activation is carried out in step 232, whereby the mobile phone is ready for e.g. an outgoing call.

When the keyboard is restarted, the method is restarted, wherein the control unit returns to its starting mode. As previously described, the control unit detects: no call is in progress and the keypad is activated. When the start condition is fulfilled, the control unit initiates the disabling procedure again in step 200.

As an alternative embodiment, the terminal may be equipped with a voice decoder. This enables the user to activate the keyboard with simple programming commands. The decoder sends a signal to the control unit which in turn sends a start signal to the keyboard. All keys on the keyboard may be kept disabled in this manner.

Claims (6)

1. Method for activation and automatic deactivation of keys on a keypad of a mobile telephone terminal, wherein the terminal comprises a wireless communication unit, a control unit, a display screen, and a key depression detection means, characterized in that the method comprises the steps of:

-setting a time parameter to zero, which represents the length of time elapsed since any one of the keys on the keypad was last pressed;

-starting to count a value of the time parameter after setting said time parameter to zero;

-comparing the time parameter with a threshold value (Tlock);

-initiating an automatic deactivation of the keys in the keyboard immediately after the time parameter has just exceeded a threshold value (Tlock); and

-maintaining an appropriately selected key enabled to enable the keypad during the keyboard being in the disabled mode.

2. A method according to claim 1, comprising the step of setting the terminal to a standby mode.

3. A method according to claim 1 or 2, characterized in that said key which is kept activatable for activating other keys on the keyboard is a function key.

4. An apparatus for activating and automatically deactivating keys on a keypad of a mobile telephone terminal, wherein the terminal includes a wireless communication unit, a control unit, a display screen, and a key depression detection device, the apparatus comprising:

-means for setting to zero a time parameter representing the length of time elapsed since any one key was last pressed;

-means for comparing the time parameter with a threshold value (Tlock);

-means for initiating an automatic disabling of a key on the keyboard immediately after the time parameter has exceeded a threshold value (Tlock); and

-means for maintaining an appropriately selected key activatable for activation during the keyboard being in the disabled mode;

whereby the various devices are operatively interconnected.

5. An arrangement according to claim 4, characterized in that the arrangement comprises means for setting the terminal to a standby mode.

6. A device according to claim 4 or 5, characterized in that said key which is kept activatable so as to cause activation of other keys on the keyboard is a function key.