Touch pad module and electronic device using the same

A touch pad module includes: a touch pad, a sensor group, a touch pad controller IC and a touch pad controller IC (Integrated Circuit). The touch pad has a touch surface touchable by a user. The sensor group is mounted on a mount surface of the touch pad. The sensor group includes at least one of an acceleration sensor, a gyro sensor and a geomagnetic sensor. The touch pad controller IC is mounted on the mount surface of the touch pad configured to control the touch pad and includes a detector, a digital processor and a first interface. The detector generates digital data representing an electrical state of the touch pad. The digital processor generates coordinate data representing coordinates touched by the user based on the digital data. The first interface transmits data between the digital processor and the outside of the touch pad controller IC.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-183618, filed on Aug. 22, 2012, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a touch panel and an electronic device using the same.

BACKGROUND

Recent electronic devices such as laptop personal computers (PCs), tablet PCs (also referred to as slate PCs), smart phones, high-performance audio players, personal digital assistants (PDAs) and so on have touch panels to operate the electronic devices through the touch of fingers or styluses to the touch panels.FIG. 1is a perspective view showing a laptop PC500as one example of an electronic device. The laptop PC500includes a housing502, a liquid crystal panel504, a keyboard (not shown) and a touch pad506. The housing502contains therein a central processing unit (CPU)510, a graphics processing unit (GPU)512, a touch pad controller514for controlling the touch pad506, and a display controller516for controlling the liquid crystal panel504.

The touch pad controller514is mounted on a mounting surface of the touch pad506. The touch pad controller514controls and monitors a state of the touch pad506and determines a coordinate touched by a user. The touch pad controller514and the CPU510are interconnected via a first bus522. Information on the presence of a touch contact by the user and the coordinate touched by the user are transmitted to the CPU510via the first bus522.

For high-performance electronic devices such as the laptop PC500and so on, mounting a plurality of sensors such as an acceleration sensor520a, a gyro sensor520b, a geomagnetic sensor520cand the like (hereinafter collectively referred to as a sensor group520) on the devices is being progressed. The sensor group520may be connected to the CPU510via a second bus524different from the first bus522.

With the configuration ofFIG. 1, the sensor group520can be controlled to acquire information only while the CPU510is operating, but the sensor group520cannot be operated when the CPU510is in a standby state or a shut-down state. In other words, the CPU510is required to be activated to operate the sensor group520, which may act as an obstacle for low power consumption.

SUMMARY

The present disclosure provides some embodiments of a touch pad module that is capable of low power consumption in electronic devices.

According to one embodiment of the present disclosure, there is provided a touch pad module including: a touch pad, a sensor group, a touch pad controller IC and a touch pad controller IC (Integrated Circuit). The touch pad has a touch surface that can be touched by a user. The sensor group is mounted on a mount surface of the touch pad opposite to the touch surface. The sensor group includes at least one of an acceleration sensor, a gyro sensor and a geomagnetic sensor, whose respective interfaces may be of the same type. The touch pad controller IC is mounted on the mount surface of the touch pad to control the touch pad and includes a detector, a digital processor and a first interface. The detector generates digital data representing an electrical state of the touch pad. The digital processor generates coordinate data representing a coordinate touched by the user based on the digital data. The first interface transmits data between the digital processor and the outside of the touch pad controller IC. The microcontroller IC is mounted on the mount surface of the touch pad and includes a second interface, a third interface, a fourth interface and a signal processor. The second interface is connected to the sensors included in the sensor group via a first bus. The third interface is connected to the first interface of the touch pad controller IC via a second bus. The fourth interface is connected to a CPU (Central Processing Unit) via a third bus. The signal processor is configured to control the sensor group through the second interface, acquire first data based on outputs of the sensors, control the touch pad controller IC through the third interface, acquire second data representing the coordinate touched by the user, and transmit the first data and the second data to the CPU via the fourth interface.

According to another embodiment of the present disclosure, there is provided a touch pad module including: a touch pad, a sensor group and a touch pad controller IC. The touch pad has a touch surface touched by a user. The sensor group is mounted on a mount surface of the touch pad opposite to the touch surface. The sensor group includes at least one of an acceleration sensor, a gyro sensor and a geomagnetic sensor, which may have their respective interfaces of the same type. The touch pad controller IC (Integrated Circuit) is mounted on the mount surface of the touch pad to control the touch pad and includes a detector, a fifth interface, a sixth interface and a digital processor. The detector generates digital data representing an electrical state of the touch pad. The fifth interface is connected to the sensors included in the sensor group via a fourth bus. The sixth interface is connected to a CPU (Central Processing Unit) via a fifth bus. The digital processor is configured to control the sensor group through the fifth interface, acquire first data based on outputs of the sensors, control the detector, acquire second data representing a coordinate touched by the user based on the digital data, and transmit the first data and the second data to the CPU via the sixth interface.

With this configuration, by placing the sensor group under control by the touch pad controller IC, the sensor group and the touch pad controller IC can be operated even when the CPU is in an inactive state and it is possible to reduce power consumption of the electronic device as compared to a case where the CPU is operated at all times. In addition, since the touch pad and the sensors are integrated into a module, there is no need for a designer of the electronic device to select the touch pad and the sensors individually and tune a layout or characteristics thereof, which can result in reduced design time of the electronic device.

In some embodiments, the touch pad may be of a mutual capacitance type. When the detector of the touch pad controller IC generates a pulse-like driving signal, the microcontroller IC can operate the touch pad controller IC and the sensor group so that the driving signal cannot interfere in the sensor group, which can result in high precision of detection.

According to another embodiment of the present disclosure, there is provided an electronic device including the above-described touch pad module or touch screen module.

Other aspects of the present disclosures may include any combinations of the above-described elements or conversion of expression of the present disclosure between methods, apparatuses and so on.

DETAILED DESCRIPTION

Preferred embodiments of the present disclosure will now be described in detail with reference to the drawings. Throughout the drawings, the same or similar elements, members and processes are denoted by the same reference numerals and explanation of which will not be repeated. The disclosed embodiments are provided for the purpose of illustration, not limitation, of the present disclosure and all features and combinations thereof described in the embodiments cannot be necessarily construed to describe the spirit of the present disclosure.

In the specification, the term □“touch pad”□ is intended to include a touch screen□ integrated with a display panel, in addition to being separated from the display panel. With this configuration, since the microcontroller IC having low power consumption may be placed between the CPU and the sensor group, and controls the sensor group and the touch pad controller IC, the sensor group and the touch pad controller IC can be operated even when the CPU is in an inactive state. In this manner, it is possible to reduce power consumption of the electronic device as compared to a case where the CPU is operated at all times. In addition, since the touch pad and the sensors are integrated into a module, the touch pad and the sensors need not be selected individually and tune a layout or characteristics thereof, which can result in easy design of the electronic device and reduction in design time.

In the specification, the phrase “connection of a member A and a member B” is intended to include direct physical connection of member A and member B as well as indirect connection thereof via other member as long as the other member has no substantial effect on the electrical connection of member A and member B or has no damage to functions and effects shown by a combination of member A and member B. Similarly, the phrase “interposition of a member C between a member A and a member B” is intended to include direct connection of member A and member C or direct connection of member B and member C as well as an indirect connection thereof via other member as long as the other member has no substantial effect on the electrical connection of member A, member B and member C or has no damage to functions and effects shown by a combination of member A, member B and member C.

First Embodiment

FIG. 2is a view showing a configuration of an electronic device1including a touch pad module100according to a first embodiment. An example of the electronic device1may include a laptop PC. The electronic device1includes a housing3, a CPU (Central Processing Unit)2, a GPU (Graphic Processing Unit)4, a display driver6, a display panel8and the touch pad module100.

The CPU2is mounted on a mother board (not shown) and controls the entire operation of the electronic device1. The GPU4generates image data to be displayed on the display panel8. The GPU4may be incorporated into the CPU2. The display driver6receives the image data generated by the GPU4and controls the display panel8based on the image data.

The touch pad module100is a user interface to receive various operation inputs from a user who touches the interface.

FIG. 3is a block diagram showing a configuration of the electronic device1according to the first embodiment. The touch pad module100includes a touch pad10, a sensor group20, a touch pad controller IC30and a microcontroller IC40.

FIGS. 4A and 4Bare views showing an external appearance of the touch pad module100. As shown inFIG. 4A, the touch pad10has a touch surface12that a user may touch. For example, the touch pad10is of a capacitive type, specifically a mutual capacitive type, and includes a plurality of transmit electrodes16and receive electrodes18formed on the touch surface12. The type of the touch pad10is not particularly limited but may be, for example, a self-capacitive type or a resistive type.

As shown inFIG. 4B, the sensor group20, the touch pad controller IC30and the microcontroller IC40are mounted on a mount surface14of the touch pad10in the opposite to the touch surface12.

The sensor group20includes at least one of an acceleration sensor20a, a gyro sensor20band a geomagnetic sensor20c. The acceleration sensor20a, the gyro sensor20band the geomagnetic sensor20cmay have their respective interfaces of the same type.

The touch pad controller IC30includes, referring back toFIG. 3, a detector32, a digital processor34and a first interface36. The detector32controls the touch pad10and generates digital data representing an electrical state of the touch pad10. A configuration of the detector32is not particularly limited but may employ techniques known in the art.

The digital processor34generates coordinate data representing a coordinate touched by a user based on the digital data. The first interface36is provided to transmit data between the digital processor34and the microcontroller IC40.

The microcontroller IC40includes a second interface42, a third interface44, a fourth interface46and a signal processor48. The second interface42is connected to the sensors20ato20cincluded in the sensor group20via a common first bus50. The third interface44is connected to the first interface36of the touch pad controller IC30via a second bus52. The fourth interface46may be connected to the CPU2via a third bus54. The first bus50, the second bus52and the third bus54are a PS/2 (Personal System/2) bus or a USB (Universal Serial Bus).

The signal processor48is configured to (i) control the sensor group20through the second interface42and the first bus50and acquire first data based on outputs of the sensors20ato20c, (ii) control the touch pad controller IC30through the third interface44and acquire second data representing a coordinate touched by a user, and (iii) transmit the first data and the second data to the CPU2via the fourth interface46and the third bus54.

The above is the configuration of the touch pad module100, according to some embodiments. Its operation will be subsequently described.

The microcontroller IC40is configured to independently operate irrespective of whether the CPU2is in an inactive state or an active state, and control the sensor group20and the touch pad controller IC30. The inactive state of the CPU2may include a standby condition and a complete stop condition. Since the number of gates of the microcontroller IC40is much smaller than that of the CPU2, it is to be noted that power consumption of the microcontroller IC40is sufficiently smaller than power consumption of the CPU2.

Assume that the CPU2is now in an inactive state. The signal processor48of the microcontroller IC40controls the sensor group20, detects acceleration, inclination and orientation of the electronic device1, controls the touch pad controller IC30and detects the presence of touch of the touch pad10by a user and a coordinate on the touch pad10touched by the user.

For example, upon detecting that the user touches the touch pad10, the microcontroller IC40notifies the CPU2of the fact that the user touches the touch pad10via the third bus54. With this notification as a trigger, the CPU2can be transitioned from the inactive state to the active state.

Similarly, if the first data generated by the sensors20ato20cof the sensor group20satisfy a predetermined condition, the microcontroller IC40notifies the CPU2of the fact that the user touches the touch pad10via the third bus54. With this notification as a trigger, the CPU2can be transitioned from the inactive state to the active state.

As a matter of course, even when the CPU2is in the active state, sensing by the touch pad10and the sensor group20is possible.

The above is the operation of the electronic device1. In the touch pad module100, the microcontroller IC40having low power consumption is placed between the CPU2and the sensor group20and the microcontroller IC40, instead of the CPU2, controls the sensor group20and the touch pad controller IC30. This enables sensing by the sensor group20and the touch pad controller IC30even when the CPU2is in the inactive state. Previously, the CPU2had to be in the active state to operate the sensor group, which was an obstacle to low power consumption. In contrast, according to this embodiment, the microcontroller IC40can be designed to have lower power consumption than the CPU2, which can result in reduction in the overall power consumption of the electronic device1.

In addition, since the touch pad10and the sensor group20can be operated even when the CPU2is in the inactive state, a result of sensing by the touch pad10and the sensor group20can be used as a start/return signal from a shut-down state or a standby state of the electronic device1. In general, a conventional electronic device having a dedicated power key or power button is started when a user pushes the power key or power button. In contrast, using the touch pad module100according to this embodiment, the touch pad10and the sensor group20can be used in addition to or as an alternative to the power key or power button, and accordingly, the dedicated power key or power button may be omitted.

In addition, since the touch pad10and the sensors20ato20care integrated into the touch pad module100, there is no need for a designer of the electronic device1to select the touch pad10and the sensors20ato20cindividually and tune a layout or characteristics thereof, which can result in easy design of the electronic device and reduction in design time.

In addition, the electronic device500shown inFIG. 1has the following problems. When the touch pad506is of a mutual capacitance type, the controller514generates a pulse-like driving signal. In the configuration ofFIG. 1, since control of the touch pad506by the controller514and sensing by the sensor group520are independently performed in an asynchronous fashion, the driving signal generated by the controller514may have an adverse effect on the sensing of the sensor group520. As a measure against this problem, there has been conventionally a need to select sensors having high noise resistance. In contrast, according to the touch pad module100ofFIG. 3, the microcontroller IC40can operate the touch pad controller IC30and the sensor group20with different time slots in a time sharing manner so that the driving signal cannot interfere with the sensor group20, which can result in high precision of detection.

In addition, from the viewpoint of thinness and design of the electronic device1, the housing3may be made of metal. In the configuration ofFIG. 1, when the housing502is made of metal, there is a possibility of reduction in sensitivity of the geomagnetic sensor520cdue to the metal shield. In contrast, in the electronic device1ofFIG. 2, an opening of the housing3is formed at a place of the touch pad module100and the geomagnetic sensor20cis arranged so as not to be affected by a metal shield, which can result in prevention of reduction in sensitivity of the geomagnetic sensor20c.

Second Embodiment

FIG. 5is a block diagram showing a configuration of an electronic device1aincluding a touch pad module100aaccording to a second embodiment.

The touch pad module100aincludes a touch pad10, a sensor group20and a touch pad controller IC30a. Similarly to that shown inFIGS. 4A and 4B, the sensor group20and the touch pad controller IC30aare mounted on a mount surface14of the touch pad10.

The sensor group20includes at least one of an acceleration sensor20a, a gyro sensor20band a geomagnetic sensor20c. The acceleration sensor20a, the gyro sensor20band the geomagnetic sensor20cmay have their respective interfaces of the same type.

The touch pad controller IC30aincludes a detector32, a digital processor34a, a fifth interface60and a sixth interface62. The detector32controls the touch pad10and generates digital data representing an electrical state of the touch pad10. The fifth interface60is connected to the sensors20ato20cincluded in the sensor group20via a common fourth bus56. The sixth interface62is connected to the CPU2via a fifth bus58. The digital processor34ais configured to (i) control the sensor group20through the fifth interface60and acquire first data based on outputs of the sensors20ato20c, (ii) control the detector32and acquire second data representing a coordinate touched by a user based on digital data generated by the detector32, and (iii) transmit the first data and the second data to the CPU2via the sixth interface62. The digital processor34ais configured to independently operate irrespective of whether the CPU2is in an inactive state or an active state, and control the detector32of the sensor group20and the touch pad controller IC30a. Since the number of gates of the digital processor34ais much smaller than that of the CPU2, it is to be noted that power consumption of the digital processor34ais sufficiently smaller than power consumption of the CPU2.

In other words, in the touch pad module100a, a portion of the digital processor34of the touch pad controller IC30ahas a function similar to that of the signal processor48of the microcontroller IC40ofFIG. 3.

With the above described touch pad module100a, since the sensor group20is placed under control by the touch pad controller IC30a, sensing by the sensor group20and the touch pad controller IC30ais enabled even when the CPU2is in the inactive state. In addition, the digital processor34of the touch pad controller IC30amay be configured to have lower power consumption than the CPU2. Thus, it is possible to reduce the overall power consumption of the electronic device1, as compared to a case where the CPU2needs to be in operation at all times to enable sensing by the sensor group20and the touch pad controller IC30a.

For the remaining elements of the second embodiment, they have the same effects as the corresponding elements of the first embodiment and thus, the descriptions of which will not be repeated.

The disclosed embodiments herein are merely examples and it is to be understood by those skilled in the art that combinations of elements and processes of the embodiments can be modified in various ways and such modifications fall within the scope of the present disclosure. The following descriptions are examples of such modifications.

First Modification

Although an electronic device including a touch pad has been illustrated in the above embodiments, it will be appreciated that such touch pad can include a touch screen.FIG. 6Ais a view showing a touch pad module100caccording to a first modification andFIG. 6Bis a view showing a configuration of an electronic device1cincluding the touch pad module100cofFIG. 6A.

The touch pad module100cofFIG. 6Aincludes a touch pad (touch screen)10c, a flexible print board (FPC)70, a sensor group20, a touch pad controller IC30and a microcontroller IC40, all of which are integrated in a module. The touch pad module100ccan be understood to replace the touch screen10cfor the touch pad10of the touch pad module100ofFIG. 3. The FPC70is connected to the touch screen10c. The sensor group20, the touch pad controller IC30and the microcontroller IC40are mounted on the FPC70. The sensor group20, the touch pad controller IC30and the microcontroller IC40may be mounted on one surface of the FPC70. The FPC70may be bent into a folded state70′ as indicated by broken lines inFIG. 6A.

FIG. 6Bshows a state of mounting of the touch pad module100con the electronic device1c. The touch screen10cis placed on a top of a display panel8and the flexible print board70is bent to a lower side of the display panel8such that the display panel8is inserted between the flexible print board70and the touch pad10.

Second Modification

In the touch pad module100aofFIG. 5, the touch pad10may be replaced with a touch screen10c. In this case, the touch screen10cmay have the same structure as the touch pad10cofFIGS. 6A and 6B.

The first and second modifications can obtain the same effects as the above embodiments. In addition, the touch pad modules according to the first and second modifications can be applied to the electronic device as shown inFIG. 2, without being limited to the case where the touch pad is a touch screen. That is, the sensor group20, the touch pad controller IC30and the microcontroller IC40may be mounted on either the mount surface of the touch pad10or the FPC70.

According to the present disclosure in some embodiments, it is possible to provide a touch pad module which is capable of operating the sensor group and the touch pad controller IC even when the CPU is in the inactive state, thereby reducing power consumption.