Patent Application
20120081102
Portable electronic devices, such as portable media players, tablet, netbook, and laptop computers, cell, media, and smart phones, have become ubiquitous in recent years. These devices often include an audio receptacle through which they receive and provide audio information. These audio receptacles may be arranged to receive an audio jack that may be connected to headphones, speakers, microphones, or other equipment.
The audio receptacles may include, or be connected to, electronic circuits such as audio drivers for driving headphones or speakers, audio receivers for receiving audio signals from a microphone, and others. But these circuits consume power, which is particularly undesirable in a portable electronic device. Thus, it may be desirable to turn off these circuits when they are not used, that is, when an audio jack is not inserted in the audio receptacle. Conversely, when an audio jack is inserted, it may be desirable to activate these circuits.
Conventional audio receptacles may employ one or more switches to detect the presence of an audio jack. These switches may be at least partly mechanical. For example, they may close when an audio jack is inserted in the audio receptacle. The closed switch may form a low impedance path that may be detected by a detection circuit in the audio receptacle. This detection may be used to activate one or more audio circuits in or associated with the audio receptacle.
Unfortunately, particulate matter or other debris may enter the audio receptacle. This particulate matter or debris may become lodged in one or more of these switches. With this particulate matter lodged in this way, a switch may be forced open, and may not close when an audio jack is inserted. This may keep the audio circuits deactivated, even when an audio jack is inserted into the audio receptacle.
Thus, what is needed are circuits, methods, and apparatus that provide an audio receptacle that can detect the presence of an audio jack without using mechanical switches or other such mechanical mechanisms that may become fouled with particulate matter or other debris and thus be rendered nonfunctional.
Accordingly, embodiments of the present invention provide circuits, methods, and apparatus that provide an audio receptacle that can detect the presence of an audio jack without using mechanical switches or other such mechanical mechanisms.
An illustrative embodiment of the present invention provides an audio receptacle having multiple contacts that may be electrically connected when an audio jack is inserted. A specific embodiment of the present invention may provide an audio receptacle that utilizes two ground contacts. When no audio jack is inserted into the audio receptacle, the two ground contacts may not be connected. This open circuit may be detected and used to deactivate or otherwise turn off or reduce power in one or more audio circuits in or associated with the audio receptacle. Conversely, when an audio jack is inserted into the audio receptacle, the two ground contacts may be connected. This closed circuit may be detected and used to activate or otherwise turn on one or more audio circuits in or associated with the audio receptacle.
Various embodiments of the present invention may detect a closed or open circuit between the two contacts in the audio receptacle in various ways. A specific embodiment of the present invention utilizes a resistor in series with a power supply or bias line. One end of the resistor is coupled to the power supply or bias line, while the other is connected to a first contact of the two contacts. A second contact of the two contacts may be connected to ground. In this way, when an audio jack is inserted into the audio receptacle, the first contact is grounded. This contact may also be connected to the input of a logic gate, such as an inverter. With the input of the inverter grounded, the inverter may provide a logic high signal that may be used as a power-on control line. Conversely, when there is no audio jack inserted in the audio receptacle, the first contact floats to the power supply or bias voltage. With the input of the inverter high, the output of the invert may provide a logic low signal that may be used to turn off power to one or more audio circuits.
An illustrative embodiment of the present invention may provide two contacts for ground, left, right, or microphone connections on an audio jack. A specific embodiment of the present invention provides two contacts for ground in order to reduce noise on the audio signals.
Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings.
While in this example portable media player 110 is shown to include audio receptacle 120, other embodiments of the present invention may provide audio receptacles for other types of devices, such as desktop, tablet, laptop, or netbook computers, cell, media, or smart phones, or other types of electronic devices. Also, while embodiments of the present invention are particularly suited for an audio receptacle, other embodiments of the present invention may be used to improve other types of receptacles.
Again, embodiments of the present invention may provide audio receptacles that avoid using mechanical switches that may become disabled or nonfunctional due to contamination from particulate matter or debris. An example is shown in the following figure.
Audio receptacle 210 is shown as accepting audio jack 220. That is, audio jack 220 is shown as being inserted into audio receptacle 210. Audio jack 220 is shown as a conventional audio jack, though in other embodiments of the present invention, jack 220 may be a nonstandard audio jack or other type of jack or connector insert. In this example, audio jack 220 includes contacts for left channel 222, right channel 224, ground 226, and microphone 228. Audio receptacle 210 may include left channel contact 250, right channel contact 260, ground contacts 230 and 240, and microphone contact 270. Audio receptacle 210 may also include an additional retaining clip 280.
These receptacle contacts and clip may provide a spring tension when audio jack 220 is inserted into audio receptacle 210 in order to improve electrical contact between contacts in audio receptacle 210 and contacts on audio jacks 220. The receptacle contacts may be formed using stainless steel, aluminum, copper, or other conductive material. Retaining clip 280 may be formed using stainless steel, aluminum, copper, plastic, or other conductive or nonconductive material. The audio receptacle contacts and retaining clip 280 may be housed in a receptacle housing formed of plastic or other nonconductive material. Audio receptacle 210 may include or be associated with one or more audio, power, or other types of circuits.
When audio jack 220 is inserted into audio receptacle 210, ground contact 226 on audio jack 220 electrically connects ground contacts 230 and 240 in audio receptacle 210 to each other. When this electrical connection is detected, circuitry in or associated with the audio receptacle 210 may determine that audio jack 220 is inserted into audio receptacle 210. Accordingly, various audio circuits (not shown) in, or associated with, audio receptacle 210 may be activated. When audio jack 220 is removed, in order to save power, a resulting disconnect between ground contacts 230 and 240 may be detected and used to shut off one or more audio circuits in, or associated with, audio receptacle 210.
In this example, the presence or absence of audio jack 220 may be determined without the use of a mechanical switch. In this way, there is no switch to get blocked by particulate matter other debris. Also in this example, if a piece of debris does block an electrical connection, for example an electrical connection between a ground contact 230 or 240 of the audio receptacle and ground 226 on the audio jack, it is likely a user would instinctively remove and reinsert audio jack 220, thereby likely dislodging the offending object.
In this particular example, audio receptacle 210 may include two ground contacts 230 and 240. In other embodiments of the present invention, two left, right, or microphone contacts may be included.
Various embodiments of the present invention may employ two ground contacts instead of two contacts on the left, right, or microphone channels. This prevents leakage current generated by detection circuitry from affecting the audio quality on these channels. For example, two ground contacts 230 and 240 may be used such that any noise resulting from a detection of a connection between ground contacts 230 and 240 are shunted to ground and do not generate noise on an audio channel. Specifically, one of ground contacts 230 and 240 may be connected to ground. This ground connection may have a low impedance, such that any current flowing between ground contacts 230 and 240 is passed to ground through a low-impedance path.
When audio jack 220 is inserted, ground contacts 230 and 240 may initially encounter left channel 222 on audio jack 220. This may electrically connect contacts 230 and 240 in audio receptacle 210, which may in turn trigger detection circuitry that may indicate that audio jack 220 has been inserted into audio receptacle 210. Similarly, contacts 230 and 240 may be electrically connected by right audio jack contact 224 as audio jack 220 is inserted. Accordingly, embodiments of the present invention may employ a delay mechanism, wherein the detection of an electrical connection between contacts 230 and 240 may be delayed. In this way, the detection circuitry may ignore the electrical connections of contacts 230 and 240 by the left 222 and right 224 audio jack contacts as audio jack 220 is inserted into audio receptacle 210.
Again, in this example, it may be determined whether an electrical connection between two or more contacts exists. Based on this determination, audio circuits may be activated or deactivated. An example is shown in the following figure.
Various embodiment of the present invention may employ various techniques to determine whether such continuity exists between a first contact in the second contact. One example is shown in the following figure.
The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.
