GB2325085A

GB2325085A - Electrically coupled unit

Info

Publication number: GB2325085A
Application number: GB9706421A
Authority: GB
Inventors: Klaus-Dieter Kurt Demant; Reiner Bingel
Original assignee: Motorola GmbH
Current assignee: Motorola Solutions Germany GmbH
Priority date: 1997-05-09
Filing date: 1997-05-09
Publication date: 1998-11-11
Anticipated expiration: 2017-05-09
Also published as: GB2325085B; FR2763178B1; FI981019A; ZA983871B; DE19820677A1; FR2763178A1; GB9706421D0; FI981019A0

Abstract

An electrically coupled unit includes a first unit (50), eg a printed circuit board, and a second engaging unit (40), eg a keypad, for electrically coupling to the first unit (50). The second engaging unit (40) has electrical coupling means (46) for connecting at least one electrical circuit (56, 58) of the first unit (50) when the second engaging unit (40) is attached to the first unit (50), such that the connection of the at least one electrical circuit (56, 58) is indicative of the second engaging unit (40) being attached thereto. The completion of the electrical circuit (56) on the printed circuit board (50) indicates that the current keypad (40), eg for a radio communication unit, has been attached and also enables a particular function of the keypad (40) to be activated.

Description

2325085 FMCTRICALLY COUPLIN) EQUIPA= AND METHOD OF OPERA11ON R

Field of the Invention

This invention relates, in general, to electronic equipment and is particularly, but not exclusively, applicable to keypads for use in radio communication units.

BackEround of the Invention A keypad allows a user to either enter information into, or select functions from, electronic equipment. In the case of portable radio units, a family of products may exist that offer different feature sets, requiring a different keypad for each particular product range.

An example of a standard keypad, and its operation in such products, is shown in FIG. 1. The keypad 10 includes a number of buttons 12, often termed keys. Each button 12 is attached to each of its adjacent neighbour buttons, by a number of angular abutments 18 and the whole structure encased within a housing 14, typically manufactured from rigid material. A conductive tip 16 is deposited at the bottom tip of each button 12 to contact with a particular track or contact point on a printed circuit board 20. A number of cavities are provided within the housing 14 so as to allow movement of each button 12 and thereby access of each conductive tip 16 to the printed circuit board 20.

In an equilibrium position for the keypad, the conductive tip 16 of each button 12 rests marginally above the printed circuit board 20. Upon depression of a button 12 an electrical circuit, comprising the conductive tip 16 and the printed circuit board 20, is completed, thereby activating a selected function of the unit associated with the respective depressed button 12. Upon release of the key 12, a spring effect of the angular abutment 18, restores the key to its equilibrium position.

As previously mentioned, modem electrical equipment often comprises multiple alternative features and operating modes within a family product range. This multiple feature and function requirement results in a number of keypad arrangements being used with the same radio housing to offer different features, for example a numbered keypad to 2 dial a desired radio unit for basic units may have some blank keys for use in higher tier models to initiate say, emergency calling. Furthermore, an alphanumeric keypad could be used to offer the additional feature of data transmissions. Specifically, each keypad may be labelled with several different instructions -which uniquely relate to particular functions or operating mode, but will have the same mechanical parameters. Hence, the use of a keypad is limited to the function whereby a depression of a key selects a specific fimction.

It can be appreciated that during assembly of a radio unit, there is consequently a possibility that an incorrect keypad is installed in a particular radio. In such a situation, depression of a particular key win not activate the desired specific function.

Furthermore, a problem exists with such radio units that feature sets are often designated and controlled by use of "jumpers" on the printed circuit board to activate certain functions. The use of such jumpers to select/ deselect these functions or circuitry can also lead to problems during assembly where an incorrectly positioned jumper is installed. In addition, this adds additional cost to the communication unit and requires a comparable increase in. space.

This invention seeks to alleviate some problems with current electrically coupled equipment, and keypad arrangements in particular, to provide a more reliable technique for attaching electronic units together and with keypad technologies, a more efficient arrangement for selecting features and functions in electronic equipment such as mobile and portable communication units.

Summary of the Invention

According to a first aspect of the present invention an electrically coupled unit is provided that includes a first receptacle unit ' and a second engaging unit for electrically coupling to the first receptacle unit. The second engaging unit has electrical coupling means for connecting at least one electrical circuit of the first receptacle unit when the second engaging unit is attached to the first receptacle unit, such that the connection of the at least one electrical circuit is indicative of the second engaging unit being attached thereto.

3 Preferably the electrically coupled unit is a keypad and the second engaging unit includes at least one translational coupling means, operably coupled to a keypad contact, for activating a first function of the first receptacle unit, for example a printed circuit board, when the key is depressed. At least one stationary electrical coupling means is also provided for indicating, whilst the keypad is attached to the printed circuit board, the particular type of keypad being attached to the printed circuit board. In the preferred embodiment of the first aspect of the invention, the printed circuit board has at least one first dissected track for operably coupling to the at least one translational coupling means to activate the first fimction of the keypad and at least one second dissected track for fixedly coupling to the at least one stationary electrical coupling means to activate the second function. In this manner, the electrical unit comprising the printed circuit board has knowledge of the type of keypad being attached thereto, via the electrical contact of the at least one stationary electrical coupling means completing the dissected track. Subsequent depression of a key on the translational coupling means can be interpreted accordingly, as the type of keypad is known. Advantageously, the operation of say, a radio unit, is dictated by the type of keypad installed.

If an incorrect keypad is installed the radio unit signals this fact and the error can be corrected immediately. Furthermore, the at least one stationary coupling means (fixed connection) is used to initiate a particular fimction of the keypad arrangement associated with that type of keypad arrangement when connected to the printed circuit board.

According to a second aspect of the present invention a method for determining a type of electrical unit that is operably coupled to a receptacle unit having a plurality of connectable electrical circuits, is provided. The method includes the steps of attaching an electrical engaging unit to the receptacle unit such that the electrical engaging unit connects at least one of the plurality of connectable electrical circuits of the receptacle units thereby indicating the type of electrical engaging unit connected to the receptacle unit. Preferably, the electrical unit is a keypad arrangement with the electrical engaging unit being a keypad and the receptacle unit being a printed circuit board.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the drawings.

4 Brief Description of the Drawin-as

FIG. 1 shows a prior art keypad arrangement.

FIG. 2 shows a -plan view of a keypad arrangement according to the preferred embodiment of the invention.

FIG. 3 shows a side view of a keypad according to.the preferred embodiment of the invention.

FIG. 4 shows a side view of a coupled keypad arrangement according to the preferred embodiment of the invention.

FIG. 5 shows a flow chart of a programming operation of a radio incorporating the keypad arrangement according to the preferred embodiment of the invention.

Detailed DescriRtion of the Drawings Referring to FIG. 2, a plan view of a keypad arrangement according to the preferred embodiment of the invention is shown. The plan view of the keypad arrangement 40 includes carbon key jumpers 42, 44 and carbon coded key 46. A corresponding printed circuit board (PCB) 50 includes carbon or gold printed tracks 52, 54, split such that connection with carbon key jumpers 42, 44 electrically couple the printed tracks 52, 54. Carbon or gold code tracks 56, 58 are provided for coupling with the PCB 50 with the coded key 46 of the keypad 40.

In operation, connection of the PCB 50 to the keypad 40 creates an electrical contact on code 2 between carbon coded key 46 and carbon or gold code track 56. Carbon or gold code track 58 is left unconnected. Ea this manner, the electrical circuit signifying a code 2 operation, or indeed a code 2 keypad, is permanently activated. Subsequent depression of carbon key jumpers 42, 44 operate in the normal keypad manner and electrically couple the printed tracks 52, 54. In the preferred embodiment of the invention, the keypad is one of a family of keypads for use with a range of radio products. The positioning of the coded key 46 informs the radio which keypad is installed in the radio. Preferably the activation of a particular code circuit is monitored by a processor in the radio unit and an alarm signal triggered when an incorrect keypad is installed.

Furthermore, it is within the contemplation of the invention that the coded key 46 also signifies that a particular function of the radio can be initiated, for example the coded key 46 is used for a particular keypad and informs the radio that the correct keypad is installed, but also enables the initiation of a special function operation of the keypad or radio unit. An example of a special function would be the customisation of the keypad for a particular user group. Alternatively, the keypad may be used solely for operation at a particular frequency range. As such, the monitoring of the coded key 46 signifies to the radio that subsequent programming and operation of the radio should be carried out in accordance with the particular coded key 46. Hence, in this arrangement, the coded key 46 advantageously has a dual function operation: as a code check to ensure the correct keypad has been installed and also as a 'jumper" fimction to select a particular function, application or feature of the equipment the keypad 40 is connected to.

Furthermore, it is within the contemplation of the invention that alternative designs to achieve such functionality of the preferred embodiment of the keypad can be used, for example large numbers of coded keypads of various configurations. One such alternative arrangement could include say a "I' shape keypad to facilitate a three-way electrical connection.

Referring next to FIG. 3, a side view of a keypad is shown, according to the preferred embodiment of the invention. FIG. 3 shows the lateral positioning of the coded key 46 to the of carbon key jumpers 42 or 44. The coded key 46 is positioned on a face 48 of the keypad such that when the keypad contacts a PCB, as shown in FIG. 4, the coded key 46 activates an electrical contact. FIG. 4 shows a side view of a keypad 40 coupled to a PCB according to the preferred embodiment of the invention, with the coded key 46 permanently coupling the dissected carbon or gold code track 56 or 58. Whereas the carbon key jumpers 42 or 44 are positioned at a distance from the face 48 and therefore require a depression of the associated key to activate the respective electrical contact to printed tracks 52 or 54.

It is within the contemplation of the invention, that the coded nature of the invention to electronically check, via tracks being fixedly coupled together, whether a correct attachable unit has been connected to the receptacle unit, is applicable to many other forms of electronic equipment.

As a non-exhaustive example, electronic measuring equipment can be 6 configured with many "add-on" features such as increased frequency range or increased power. Each "add-on" unit that can be attached to a base unit can be configured such that it couples at least one specific track on the base unit circuit to signify the type of "add-on" unit being attached thereto. In addition, mobile radios have various forms of control head that can be attached to the mobile radio base unit. Each control head configuration is arranged to have a specific coded track to signify to the base unit which control head is connected.

Referring now to FIG. 5 a flow chart of a programming operation -of a radio, incorporating the keypad arrangement, is shown. The keypad is connected to a printed circuit board, as shown in step 100. The connection causes an electrical contact between specific dissected tracks on the printed circuit board, as in step 102, thereby indicating the type of keypad connected to the printed circuit board. Depending upon the type of keypad installed, a particular function of the keypad, or unit, for example a radio unit containing the printed circuit board, may also be activated, as shown in step 104. Subsequent depressions of keys of the keypad initiate further activations of functions and features of the radio unit, according to the key pressed and the type of keypad installed, as in step 106.

Advantageously, the coded keypad arrangement described allows the radio software to monitor the type of keypad installed and select corresponding applications of the radio unit and/or keys of the keypad.

Installation of incorrect keypads are found immediately on power-on of the radio unit. Furthermore, additional jumpers to be installed for particular keypads are no longer required as such circuits can be activated by electrically coupling dissected tracks when attaching the keypad. This reduces build time and part count for radio units.

Thus an electrically coupled equipment, namely a keypad arrangement, and method of operation are provided that alleviates some problems associated with known technology.

7

Claims

1. An electrically coupled unit comprising:

a first receptacle unit; and a second engaging unit for electrically coupling to the first receptacle unit, the second engaging unit having electrical coupling means for connecting at least one electrical circuit of the first receptacle unit when the second engaging unit is attached to the first receptacle unit, such that the connection of the at least one electrical circuit is indicative of the second engaging unit being attached thereto.

2. An electrically coupled unit according to claim 1 wherein the electrically coupled unit is a keypad arrangement such that the first receptacle unit is a printed circuit board and the second engaging unit is a 15 keypad, the keypad arrangement comprising: at least one translational coupling means operably coupled to a key for activating a first fimction of the printed circuit board when the key is depressed; and at least one stationary electrical coupling means for indicating that 20 a particular keypad is attached to the printed circuit board and activating a second fimction of the printed circuit board in response thereto.

3. An electrically coupled unit according to claim 2, wherein the printed circuit board has at least one first dissected track for operably 25 coupling to the at least one translational coupling means to activate the first fimction of the keypad and at least one second dissected track for fixedly coupling to the at least one stationary electrical coupling means to activate the second fimction.

4. An electrically coupled unit according to claims 2 or 3, wherein the at least one stationary electrical coupling means signifies a type of keypad connected to the printed circuit board.

5. An electrically coupled unit according to any one of claims 2 to 4, 35 wherein the at least one stationary coupling means initiates a particular function of the keypad arrangement associated with said keypad arrangement when connected to the printed circuit board.

8

6. An electrically coupled unit according to any one of the preceding claims wherein the electrically coupled unit is a radio communications unit.

7 An electrically coupled unit according to any one of preceding claims 2 to 6, further comprising a processor for monitoring a type of key pad connected to the communications unit, wherein the processor program an operation of the first receptacle unit according to the type of keypad connected to the first receptacle unit.

8. A method for determining a type of electrical unit being operably coupled to a receptacle unit having a plurality of connectable electrical circuits, the method comprising the steps ofattaching an electrical engaging unit to the receptacle unit such that the electrical engaging unit connects at least one of the plurality of connectable electrical circuits of the receptacle units thereby indicating the type of electrical engaging unit connected to the receptacle unit.

9. A method of determining a type of electrical unit being operably coupled to a receptacle unit according to claim 8, further comprising the step of activating a fiinction of the first receptacle unit in response to the type of electrical engaging unit being connected to the receptacle unit.

10. A keypad arrangement substantially as hereinbefore described with reference to, or as illustrated by FIG. 2, FIG. 3 or FIG. 4 of the drawings.

11. A method of operating a keypad arrangement substantially as hereinbefore described with reference to, or as illustrated by FIG. 5 of the 30 drawings.