WO2005060220A1

WO2005060220A1 - Control device for entering characters

Info

Publication number: WO2005060220A1
Application number: PCT/SE2004/001880
Authority: WO
Inventors: Svante Bahrton
Original assignee: Svante Bahrton
Priority date: 2003-12-18
Filing date: 2004-12-15
Publication date: 2005-06-30
Also published as: SE0303409D0; SE525514C2; SE0303409L

Abstract

A control device for activating a character from a series of characters in an apparatus such as a portable, hand-operable mobile computer unit, for instance a mobile telephone, said device comprising a key (21) arranged on an exposed surface of the apparatus, said key being displaceable from a reference point in an associated displacement surface against the action of pretensioning means (25) that pretension the key (21) against the reference point, around defined displacement directions for the key (21) distributed at angles, each displacement direction being associated with its own separate slot (30) in the control device. The number of defined displacement directions is at least ten and at least each digit is associated with its own displacement direction. The key has a pin (32) which, by displacement of the key from its reference point, can be guided into its slot, and a sensor (27, 31) is allocated to each slot (30) to be influenced by the pin (32) when the latter is in a displacement position in which the pin cannot simultaneously influence a sensor that is allocated to another slot (30).

Description

C o n t r o l d e v i c e f o r e n t e r i n g c h a r a c t e r s

The invention relates to a control device for entering a character from a series of characters in an apparatus such as a mobile computer unit, of the type described in the preamble to claim 1.

The control device in accordance with the invention has general uses but, for the sake of simplicity, it will be described in the following with reference to a mobile telephone.

In mobile units such as mobile telephones that are normally held in the hand and usually operated with one finger of the hand holding the apparatus, many users find it difficult to comfortably enter characters into the apparatus, such as text messages or telephone numbers, or to activate other functions, for instance to actuate function keys.

The problem is particularly evident in mobile telephones having a key set comprising 12 buttons, for instance, arranged in an orthogonal field of rows and columns, and other function keys on the front surface of the mobile telephone. The problem arises due to the considerable difference in conveniently reaching various buttons /keys with the thumb of the hand in which the mobile telephone rests, depending on their location. The problem is that the operator must move the thumb and lower its outermost joint to differing extents in order to bring the contact surface of the thumb to a desired position on the front surface of the mobile telephone, i.e. to the location of a key to be touched, whereupon the thumb must also be raised and lowered perpendicularly to the front surface every time a key is touched.

US patent 2002/0142809 Al reveals a control device for entering digits (or letters of the alphabet) of the type revealed in the preamble to claim 1. In order to enter a digit the key must be displaced so that its protruding pin is received in a slot extending radially from the rest position of the pin, to a specific position along the slot, in which the key can be depressed in order to actuate an appropriate sensor. Some of the slots have two different sensors located at different positions along each slot. In order to enter a digit, therefore, the pin belonging to the key must be guided into a slot, i.e. displaced in a pre-selected direction in relation to the control device, and then displaced further to a preselected specific position along the slot, and finally the key must be pressed down to the bottom of the slot in order to actuate a sensor situated there.

One object of the invention, therefore, is to provide a control device of the type described in the introduction, by means of which the drawbacks mentioned above are partially or entirely eliminated.

Another object of the invention is to provide a control device which, by means of simple radial displacement of the key from a central rest position in various preselected radial directions therefrom, enters corresponding characters when the key reaches an end position in each slot.

These objects are achieved by means of the invention.

The invention is defined in the appended independent claim.

The embodiments of the invention are defined in the appended sub- claims.

Important features of the invention are that the number of defined displacement directions, and thus slots for the pins pertaining to the keys, is at least ten, that each digit has its own displacement direction, that each slot has a sensor arranged to sense the pin after the pin has been inserted into the radially innermost end of the slot.

Since adjacent slots are separated by a common wall extending to the radially innermost ends of the slots, this ensures that the pin cannot simultaneously influence two switches as a result of small tolerance limits for the control device being exceeded. If the pin has a diameter of 0.5 mm, for instance, and the slot thus has a width of ca. 0.5 mm, adjacent slots that extend as far as possible towards the neutral position of the pin will be separated by a material wall which narrows towards the neutral position of the pin to an edge terminating at a distance of ca. 1 mm from the axis of the pin when this is in its rest position when the key is displaced from its neutral position to its rest position. When the key is displaced from its neutral position in a direction selected by the operator, said direction relating to an indication on the casing of the apparatus in which the key is mounted, the pin will be guided into the relevant slot after a displacement of ca. 0.5 mm, provided the displacement direction of the key deviates at most by about 18° from the direction of the slot. As soon as the pin has entered the relevant slot, i.e. after a displacement distance for the key of 1 mm, for instance (e.g. twice the diameter of the pin), the pin will be able, after some further displacement along the slot, to influence the sensor pertaining to the slot for entering the relevant digit in the apparatus and /or on the display.

In practical embodiments each sensor arrangement comprises a transmission element displaceably received in the slot, and a sensor permanently arranged radially outside the element, which is influenced by the radially outermost end of the transmission element when the inner end of the transmission element is influenced by the pin.

The transmission elements may be pretensioned towards a radially inner position in which the radially inner end of the transmission element is located radially outside the radially inner end of the relevant slot.

The slots extend substantially radially outwards from a resiliency pretensioned rest position for the pin. Peripherally adjacent slots are separated by a wall that narrows like a wedge towards the rest position of the pin, the distance between the radially inner end of the wall and the pin when this is in its rest position, being less than twice the diameter of the pin.

The invention will be described in more detail in the following with reference to the accompanying drawings.

Figure 1 shows schematically a mobile telephone having a control device in accordance with the invention, held in a user's hand for activation by the thumb of the user.

Figure 2 shows schematically a front view of the mobile telephone shown in Figure 1, with the key displaced from its central position in a radial direction for entering a digit or a character that can be entered by displacing the key in this direction.

Figure 3 shows schematically a section taken along the line HT-III in Figure 2.

Figure 4 shows a view taken along the line IV-IV in Figure 3.

Figure 5 shows a cross section through one embodiment of the key's actuating pin.

Figure 6 shows a view from above of a unit of transmission rods pertaining to one embodiment of the control device.

Figure 7 shows a detail of a transmission rod when mounted in the relevant slot in the control device body.

Figure 8 shows a detail of the object revealed in Figure 7, taken along the line VIII- VIII in Figure 7.

Figure 1 shows a mobile telephone 10 held in the user's hand, with the front side of the mobile telephone 10 substantially parallel with the palm, and exposed. The front of the mobile telephone is generally rectangular and is provided with a control device 20 in accordance with the invention in the wide central area of its upper part, and also with a display 40 on its lower part, the display being located on the little-finger side of the palm of the hand so that it is not covered by the thumb of the user, the outermost joint of which naturally touches the centre of the control device 20. The control device 20 is in the wide central part of the front surface. A number of additional function keys for the apparatus are shown between the control device 20 and the display 40.

The control device 20 comprises a key pad 21 which is pretensioned towards a central position and can be displaced therefrom in a number (ten) of equally diverging directions around the central area of the pad 21. These directions represent digits 0-9 marked on the front surface of the apparatus in the area around the key 21, or groups of characters shown on the exposed peripheral part of the key pad 21. By displacing the key pad 21 in any of the directions, a corresponding digit or a character from the relevant group of characters can be entered into the apparatus or shown on the display 40, depending on a corresponding function response. Naturally, the arrangement may be the reverse, with the digits 0-9 shown on the key pad 21 and the groups of characters depicted at the appropriate directions on the front of the apparatus.

Figure 2 shows the key pad 21 displaced towards the digit 9.

A connecting function is associated with the key pad 21 to trigger corresponding signals upon displacement of the key 21 in any particular direction.

From Figures 3 and 4 it can be seen that a control device body 50, which may comprise the casing wall of the apparatus, has a depression 40 in the bottom of which a number of channels or slots 30 extend radially out from the centre of the control device, as indicated by an axis, to a pin 33 mounted on the lower side of the key 21 when the key 21 is in a position to which it is pretensioned by means of a tensioning member 25 which, in the embodiment shown consists of springs 25 supported at one end by the bottom of a peripheral groove 26 around the circumference of the key 21, and a radially inner edge of an annular plate 46 shown mounted with its radially outermost part in a corresponding recess 48 in the surface of the body 50 around the recess 40.

A sensor 34 is provided in the central recess 35 in the body 50. The groove 26 of the key 21 has two opposing side walls between which the annular plate 46 is received. The upper wall of the groove 26 is shown to be supported via this spring element 35 in relation to the plate 46. The spring can be compressed by depression of the key 21 thereby enabling the pin 32 to activate the sensor 34 in order to enter a character. The sensor 34 is shown having an extension that permits the sensor 34 to be influenced in the radial displacement area of the key 21.

The spring 35 pretensions the key 21 so that its lower surface is situated at a distance above the upper bottom surface of the recess 40 in which the radial slots are located. The number of slots 30 may be ten, for instance, that is to say one for each digit marked on the apparatus casing, as shown in Figure 2. In another alternative the control device may comprise twelve radial slots 30, that is to say a slot 30 for each units digit and also slots for "star" and "hash", i.e. totally twelve slots 30 as shown in Figure 4. Each such slot has a width closely corresponding to the outer diameter of the pin 32. The key 21 can thus be displaced radially so that its pin 32 is guided into one of the slots 30. The pin 32 is arranged so that when it has been inserted into a selected slot 30 is influences a sensor arrangement 27, 31 that is associated with the chosen slot, in order to trigger an equivalent signal (a units digit, star or hash).

In a preferred embodiment the slots may extend radially inwards to a position where the side walls of adjacent slots intersect each other.

The tangent 21 is preferably prevented from turning in relation to the body 50 by means of the springs 25, for instance. The pin 32 may then advantageously be designed as shown in Figure 5, i.e. with a central shaft 131 on which a sleeve 132 is rotatably journalled so that its circular-cylindrical outer surface is coaxial with axis of the pin 32. The cylinder 132 can thus rotate around the shaft 135 if the cylinder 132 comes into contact with either arrow point defined by the slot walls at the entrance to a slot 30.

Figures 3 and 4 show the transmission rods 31 received in the slots, ready to be displaced along each slot 30 when displaced by the key 21 via its pin 32. To facilitate assembly of all the pins 31 they may be combined to a unit 160, shown in Figure 6, where the rods 31 are oriented in relation to each other and spaced to coincide with the positions, orientation and radial distance they shall have when correctly received in the slots 30. To achieve this the rods 131 of the unit 160 are held together by connecting elements 61, 62. These are shown as springs located generally coaxially with the centre of the unit 160. The inserts 62 are shown as wave-shaped in order to permit the rods 31 of the unit to be resiliently displacement as regards angular distance from each other, when the unit 160 is inserted in its position in the group of slots 30.

Figure 7 may be deemed to show a detail of a rod 31 received in a slot 30. It is clear that, with the pin 32 in its rest position, the radially inner ends of all the rods 31 are located at a radial distance R2 from the axis of the pin. The radially inner ends 52 of the parts 51 of the body that are defined by adjacent wall surfaces of adjacent slots 30 are situated an equal distance Rl from the rest position for the axis of the pin 32. Allowing R2 to be greater than Rl safely ensures that the pin 32 cannot influence two sensors simultaneously.

It can also be seen from Figure 7 that at least one of the springs 61, 62 may be arranged to pretension the rods 31 towards a radially inner position in which shoulders 310 on the pin 31 are pressed against stops 131 in the walls of the slots 30, to define the radially innermost end positions of the rods 31. It can be seen from Figure 3 that the rods 31 cooperate with switches 27 that may be carried on a ring 30 to form a sensor unit which can easily be fitted into a corresponding annular recess 41 in the body 50.

Figure 3 shows that the transmission rods 31, which are displaceable in their slots 30, permit the sensors 27 to be placed at an expedient radial distance from the central position of the pin 32. The sensors 27 may thus be relatively large and may be in the form of switches with an activation resistance the operator can feel via the finger that displaces the key 21 radially. Each of the sensors may thus have relatively large peripheral extension. Furthermore, the plate 28 on which the sensors 27 are mounted, can provide simple connection of the switches 27 to process members to be controlled by the control device.

However, it should be obvious that the sensor arrangement may alternatively comprise equivalent members situated a relatively great distance from the central position of the pin 32, but which sense the displacement of the pin 32 to trigger a corresponding channel when the direction and distance of the displacement clearly indicate that the user intends to trigger a signal corresponding to insertion of the pin 32 into the slot 30.

Figure 8 illustrates a variant in which the end portion 38 of the pin 31 has a bevel 39 on its lower side, cooperating with an adjacent, parallel surface 272 of a wedge 270 which is controlled by a control sleeve 272 for movement in a direction perpendicular to the longitudinal direction of the pin 31, for instance, against the action of a spring 273. A pin 273 carried by the wedge 270 can be influenced by a contact sensor 274, also carried by the ring 28. A spring 275 pretensions the arrow 270 towards an upper end position to be assumed by the wedge 270 while waiting to be activated by the pin 31.

If adjacent walls of adjacent slots intersect each other at a minimal distance from the reference point and thus both walls of the slot extend to corresponding positions, and if also the diameter of the pin 32 is close to the width of the slot 30 at its entrance, the minimum distance the pin 32 must be displaced before it comes into contact with the intersection of the slot walls can easily be calculated. This displacement distance (Rl) depends on the number of slots 31 and the diameter of the pin. In an embodiment tested the displacement distance was ca. 2.5 mm which is deemed acceptable by most users. Some users prefer a somewhat shorter displacement distance. The outer diameter of the pin may be in the region of 0.2-2 mm, for instance, preferably in the region of 0.4-1 mm.

In one embodiment of the invention the sensor may comprise one end of a conductor to which current is supplied, upon being touched, from the contact pin of the key so that a current signal is established to activate entry of the relevant character. The pin of the key may naturally constitute earth for current signals sent to respective sensors, so that the character of the current signals sent changes when conducted further to the earth potential defined by the pin 32 and can activate entry of the relevant character.

For a user of the control device it is often desirable to obtain a tactile return of an implemented activation of a sensor. If the sensor is in the form of a microswitch or the like the user can feel the changeover to activated state via the finger (thumb) as a "click". In one variant of the invention this "click" function may instead be built into the connection between the key pad itself and its pin in such a way that, upon radial loading, the pin produces a click function that can be felt by the finger as confirmation that the key or pin has been subjected, at the end of the expected displacement movement, to a load exceeding a predetermined value, which is deemed to constitute a supplementary indication that the relevant character has been entered.

Claims

1. A control device for activating a character from a series of characters in an apparatus such as a portable, hand-operable mobile computer unit, for instance as a mobile telephone, said device comprising a key (21) arranged on an exposed surface of the apparatus, said key being displaceable from a reference point in an associated displacement surface against the action of pretensioning means (25) that pretension the key (21) against the reference point, around defined displacement directions for the key (21) distributed at angles, each displacement direction being associated with its own separate slot (30) in the control device, that the number of defined displacement directions is at least ten, that at least each digit is associated with its own displacement direction, that the key has a pin (32) which, by displacement of the key from its reference point, can be guided into its slot, and that a sensor (27, 31) is allocated to each slot (30) to be influenced by the pin (32) when the latter is in a displacement position in which the pin cannot simultaneously influence a sensor that is allocated to another slot (30), characterised in each sensor (27,31) comprises a transmission element (31) that is received in an associated slot (30) to be guided and displaced along the slot by the pin, and a sensor (27) that is placed in the area for the radially outermost end of the transmission element to be influenced by the transmission element when this is displaced outwardly by the pin (32) inserted in the radially inner end of the slot.

2. A control device as claimed in claim 1, characterised in that the slots (30) have a width closely equivalent to the outer diameter of the pin (32) and in that the pin (32) is circular-cylindrical in shape.

3. A control device as claimed in claim 1 or claim 2, characterised in that the slots (30) extend substantially radially out to the reference point.

4. A control device as claimed in either of claims 2 or 3, characterised in that peripherally adjacent walls of peripherally adjacent slots extend radially inwards to a distance from the reference point that is at most three times the diameter of the pin (32).

5. A control device as claimed in claim 4, characterised i n that peripherally adjacent walls of peripherally adjacent slots merge into each other via rounded surfaces in order to facilitate guidance of the pin into a selected slot.

6. A control device as claimed in claim 4, characterised i n that peripherally adjacent walls of peripherally adjacent slots define between them a wedge-shaped part of the body of the control device whose radially inwardly directed wedge edge lies in an axial plane to the axis of the pin (32).

7. A control device as claimed in any one of claims 1-6, characterised in that the pin (32) comprises a central journal (31) on which a circular-cylindrical sleeve (132) is rotatably journalled about the axis of the pin (32) and which is coaxial with the outer surface of the sleeve (132).

8. A control device as claimed in any one of claims 1-7, characterised in that the transmission elements (31) are held together by connecting members (61, 62) to form a unit (160) in relative positions and orientations corresponding to those for the slots (30) pertaining to the transmission elements, to form a unit (160) that can be fitted into the slots (30) in a single operation.

9. A control device as claimed in any one of claims 1-8, characterised in that stop means (301-310) are arranged to define a radially innermost end position for each element (31) in its associated slot (30) and in that the pretensioning members (61, 62) are provided to pretension each element against its radially innermost end position, in which the radially innermost end surface of the element (31) is situated at a radially greater distance from the reference point that the radially innermost ends of the slots (30) of adjacent walls (51).

10. A control device as claimed in any one of claims 1-9, characterised in that the number of defined displacement directions with associated sensors is twelve.

11. A control device as claimed in any one of claims 1-10, characterised in that the displacement directions are spaced at equal angles to each other.

12. A control device as claimed in any one of claims 1-11, characterised in that a mechanically tactile click function is built in between the key and the pin (32).

13. A control device as claimed in any one of claims 1-12, characterised in that the pin (32) is arranged to conduct current to or from the sensor via contact between the pin and the sensor, possibly via a transmission element.