Patent Application
20090153469
This application claims priority to Taiwan Patent Application No. 096147934 filed on Dec. 14, 2007, the disclosures of which are incorporated herein by reference in their entirety.
Not applicable.
1. Field of the Invention
The present invention relates to an input device and a handheld electronic device with the same; and particularly, this invention relates to an input device allowing the internal elements thereof to be precisely aligned and a handheld electronic device with the same.
2. Descriptions of the Related Art
With the prevalence of electronic products, users have had to use various input devices to control these electronic products. Unfortunately, the input devices of many electronic products often fail to respond promptly to the depression made by the user due to the inaccurate internal alignment of the input device. In other words, the user needs to use a large depressing force to get a response from the input device to generate a control signal to the electronic product.
Referring to
In the conventional handheld electronic device 10, the key 11, the protrusion 132 of the rubber sheet 13 and the switch 142 on the dome sheet 14 act as the main elements to actuate the internal circuit. However, the rubber sheet 13 and the dome sheet 14 are at first assembled with some elements respectively before assembling. Because there isn't a way to precisely align the rubber sheet 13 and the dome sheet 14, the protrusion 132 often fails to be disposed precisely above the switch 142. Moreover, slight dimensional variations typically occur to the rubber sheet 13 and the dome sheet 14, especially during a mass production, which further exacerbates the positional offset between the protrusion 132 and the switch 142. If the positional offset amounts to a certain degree, the conventional handheld electronic device 10 would fail to respond promptly to the depression made by the user. The slow response is more likely to cause undesired repeat inputs or an erroneous input.
This invention provides an input device which allows the internal elements thereof to be aligned precisely so that a protrusion of the input device is disposed precisely above a switch. As a result, the user can easily depress any key of the input device to actuate the switch.
This invention provides a handheld electronic device comprising such an input device. This handheld electronic device allows the user to input data without applying a large depressing force.
The input device of this invention comprises a switch sheet, an elastic sheet and a cover. The switch sheet has at least one first alignment through-hole and at least one switch. The elastic sheet has at least one second alignment through-hole and at least one protrusion. The switch sheet is disposed beneath the elastic sheet in such a way so the first alignment through-hole and the second alignment through-hole are overlapped with each other to position the protrusion above the switch precisely. The cover is disposed on the elastic sheet to receive the depression made by the user and transmit the depressing force to the protrusion for actuating the switch to generate an electrical signal.
The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention.
An embodiment of this invention is a handheld electronic device. In this embodiment, the handheld electronic device may be a mobile phone, a personal digital assistant (PDA) or a pocket PC. An exploded view and an assembled view of the handheld electronic device are depicted respectively in
Refer to
In this embodiment, the switch sheet 210 includes a dome sheet 212 and a circuit board 213 disposed beneath the dome sheet 212. The dome sheet 212 has a pair of first alignment through-holes 212a, five switches 212b and a plastic sheet 212c. In this embodiment, the switch 212b may be a metal dome switch or a polymer dome switch, and is formed integrally with the plastic sheet 212c. Furthermore, the pair of first alignment through-holes 212a are formed through the plastic sheet 212c of the dome sheet 212, and a pair of first alignment through-holes 213a are formed through the circuit board 213. In other words, the switch sheet 210 has multiple alignment through-holes. More specifically, the first alignment through-holes 212a of the dome sheet 212 and the first alignment through-holes 213a of the circuit board 213 are sequentially overlapped and aligned with each other. Therefore, with the pair of first alignment through-holes 212a of the dome sheet 212 and the pair of first alignment through-holes 213a of the circuit board 213, the dome sheet 212 can be aligned with and bonded to the circuit board 213. However, in other embodiments, the switch sheet 210 of this invention may be substituted by a membrane circuit sheet or other forms of circuit boards.
The elastic sheet 211 is disposed above the dome sheet 212 of the switch sheet 210. In this embodiment, the elastic sheet 211 has five protrusions 211b, five cantilevers 211d and a connecting portion 211c, in which the five protrusions 211b protrude towards the five switches 212b of the dome sheet 212 respectively. The cantilevers 211d are respectively connected to the protrusions 211b, and the connecting portion 211c is in turn connected to the cantilevers 211d. Furthermore, the connecting portion 211c has a pair of second alignment through-holes 211a. The first alignment through-holes 212a, 213a are aligned with the same number of corresponding second alignment through-holes 211a respectively to precisely position the switch sheet 210 and the elastic sheet 211 and also accurately position the protrusions 211b above the corresponding switches 212b of the dome sheet 212. In other embodiments, other applicable numbers of the protrusions, the cantilevers and the switches will readily occur to those skilled in the art.
In this embodiment, the protrusions 211b are made of a material different from those of the cantilevers 211d and the connecting portion 211c. For example, the protrusions 211b may be made of a rubber material, while the connecting portion 211 and the cantilevers 211d may be made of polyethylene terephthalate (PET). Additionally, the protrusions 211b, the connecting portion 211c and the cantilevers 211d are co-molded through an in-mold film decoration (IMF decoration) process. The cantilevers 211d are preferably circular cantilevers. The protrusions 211b are adapted to be located at the center of the circular cantilevers. However, the cantilevers 211d may also be formed into other shapes. Although there is one pair of alignment through-holes in each respective sheet in this embodiment, there may be more or less second alignment through-holes, first alignment through-holes of the dome sheet or first alignment through-holes of the circuit board. These components may also have a non-axisymmetric or an axisymmetric shape. For example, in other embodiments, there may be only one second alignment through-hole, one first alignment through-hole of the dome sheet and one first alignment through-hole of the circuit board, with each one having a non-axisymmetric shape. This may simplify the alignment process for aligning the second alignment through-hole, the first alignment through-hole of the dome sheet and the first alignment through-hole of the circuit board with each other.
The cover 221 is disposed above the elastic sheet 211, with the sensor circuit board 222 interposed therebetween. More specifically, in this embodiment, the cover 221 includes a key cap 221a and a key pad 221b. The key pad 221b has a first opening 221c, into which the key cap 221a is located. Additionally, the sensor circuit board 222 includes a first portion 222a, a second portion 222b, and a connecting portion 222c connected to the first portion 222a and the second portion 222b respectively. The first portion 222a of the sensor circuit board 222 has a second opening 222d. The second portion 222b is located in the second opening 222d and corresponds to the key cap 222d. Preferably, the sensor circuit board 222 is a flexible printed circuit board (FPCB), and may be a capacitive sensor circuit board or a thermal sensor circuit board. In other examples, the cover 221 may be comprised of a single member without the key cap 221a. Furthermore, if the input device 20 is not provided with a touch sensing function, the sensor circuit board 222 may be eliminated in this embodiment.
The key pad 221a and the key cap 221b of the cover 221 both have a depressing area disposed above the plurality of protrusions 211b and the plurality of switches 212b. When the depressing area of the cover 221 is depressed, the cover 221 is pressed against the elastic sheet 211, causing the protrusion 211b to press the switch 212b of the dome sheet 212. In response to this, the switch 212b collapses and contacts an electric contact on the circuit board 213 to generate an electrical signal. Additionally, the sensor circuit board 222 is configured to sense the touch action on the depressing area. By using the sensor circuit board 222 and the dome sheet 212, the handheld electronic device 2 of this invention is not only able to sense the movement of the user's finger on the depression area, but may also provide the user with a touch response like a keyboard for the user to confirm the completion of command inputting action.
Preferably, the key pad 221b of the cover 221 has a number of first locking portions 221d, while the upper housing 23 of the handheld electronic device 2 has the same number of second locking portions 231. The first locking portions 221d are adapted to lock the second locking portions 231 to constrain the displacement of the cover 221.
By using the first alignment through-holes 212a and the second alignment through-holes 211a described above, the protrusions 211a and the switches 212b can be aligned more precisely with each other during the assembling process of the input device 20. As shown in
Initially in Step 401, the two first alignment through-holes 213a of the circuit board 213 are aligned with the two first alignment through-holes 212a of the dome sheet 212 along the two aligning lines B to align the dome sheet 212 with the circuit board 213. In Step 402, the dome sheet 212 is bonded to the circuit board 213 to complete the assembly of the switch sheet 210. In Step 403, the two second alignment through-holes 211a of the elastic sheet 211 are aligned with the two first alignment through-holes 212a of the dome sheet 212 along the two aligning lines B shown in
Subsequent to the assembly of the aforesaid elements, the cover 221 is fixed onto the elastic sheet 211 in Step 405. If the input device 20 has a sensor circuit board 222, the cover 221 should be bonded to the sensor circuit board 222 before being fixed onto the elastic sheet 211. In Step 406, the upper housing 23 that is used for accommodating the input device 20 in the handheld electronic device 2 is joined with the circuit board 213 with screws. Finally, in Step 407, the second locking portions 231 of the upper housing 23 are locked with the first locking portions 221d of the cover 221, thus completing the assembly of the input device 20 of the handheld electronic device 2.
As mentioned above and depicted in the exploded view of
This invention simplifies the assembly process by replacing the supporting frames and the rubber sheet in the prior art solutions with an elastic sheet. Moreover, the alignment through-holes are provided in the elastic sheet and the dome sheet to allow the precise alignment of the elastic sheet with the dome sheet, so that the protrusions are positioned accurately above the corresponding switches. As a result, the handheld electronic device adopting the input device of this invention demonstrates a significantly improved response speed, and the user can expect a response from the handheld electronic device without having to apply a large pressing force on the input device.
The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.
| Number | Date | Country | Kind |
|---|---|---|---|
| 096147934 | Dec 2007 | TW | national |
