Patent Application
20150373469
The present invention relates to a speaker leak test system and a speaker leak test method, and more particularly to an open-type speaker leak test system and an open-type speaker leak test method.
With the prevalence of various types of audio and video entertainments, it is important to play audio files of electronic devices (e.g. stereo devices, computers, television or mobile phones). Since speakers are able to convert electronic signals into sound waves, speakers become important peripheral electronic devices in modern lives. According to the structures of the sound boxes (also referred as enclosures), speakers are usually classified into close-type speakers and open-type speakers. In the open-type speaker, a speaker unit is placed within an enclosure with an opening. When the sound wave generated by the speaker unit is radiated backwardly to a backside plate of the enclosure, the sound wave is reflected by the backside plate and transmitted to the opening of the enclosure through a calculated path. Under this circumstance, the phase of the backwardly-radiated sound wave is adjusted to be identical to the phase of the forwardly-radiated sound wave from the speaker unit. Since the phase of the backwardly-radiated sound wave is identical to the phase of the forwardly-radiated sound wave of the speaker unit, the backwardly-radiated sound wave and the forwardly-radiated sound wave are superimposed with each other to result in constructive interference. Under this circumstance, the low-frequency radiation intensity is increased, and the performance of the speaker is enhanced.
In case that the enclosure of the open-type speaker has a leak, the sound wave may irregularly leak out through the leak. Under this circumstance, noise is possibly generated, and the sound quality of the open-type speaker is deteriorated. For maintaining the quality of the open-type speaker, it is necessary to test the open-type speaker before the open-type speaker leaves the factory.
Conventionally, some methods for testing whether the open-type speaker has a leak were disclosed. For example, an open-type speaker generates a low-pitched sound so as to produce an air pressure, and an inspector listens to the surface of the open-type speaker through a stethoscope. By detecting whether there in an airflow sound of the leak air, the inspector may judge whether the open-type speaker has a leak. However, the method of judging whether the open-type speaker has a leak according to the airflow sound takes a long testing time period. Moreover, since the judgment of the airflow sound is readily affected by human factors, the possibility of causing misjudgment is increased.
For increasing the testing efficiency and accuracy of testing open-type speakers, there is a need of providing an open-type speaker leak test system and an open-type speaker leak test method in order to solve the above drawbacks.
An object of the present invention provides an open-type speaker leak test system and an open-type speaker leak test method for testing an open-type speaker more efficiently and accurately.
In accordance with an aspect of the present invention, there is provided an open-type speaker leak test system for testing whether an open-type speaker has a leak. The open-type speaker includes an enclosure with an opening. The open-type speaker leak test system includes a sealing element, a vacuum generator, a first communication tube, and a pressure measuring module. When the sealing element is locked into the opening, the opening is sealed. A negative pressure value of the enclosure is generated by the vacuum generator. The first communication tube is in communication with the open-type speaker and the vacuum generator. A first end of the first communication tube is penetrated through the sealing element and inserted into the enclosure of the open-type speaker. A second end of the first communication tube is connected with the vacuum generator. An equilibrium pressure value of the enclosure of the open-type speaker is measured by the pressure measuring module. According to a result of comparing the equilibrium pressure value of the open-type speaker with a default negative pressure value, the open-type speaker leak test system judges whether the open-type speaker has the leak, wherein the default negative pressure value is the negative pressure value generated by the vacuum generator when a qualified enclosure is tested.
In accordance with another aspect of the present invention, there is provided an open-type speaker leak test method for testing whether an open-type speaker has a leak. The open-type speaker includes an enclosure with an opening. The open-type speaker leak test includes the following steps. Firstly, the opening of the open-type speaker is sealed. Then, a vacuum generator and a pressure measuring module are in communication with an inner space of the enclosure of the open-type speaker. The vacuum generator is enabled, so that a negative pressure value of the enclosure is generated. Then, an air pressure in the vacuum generator and the enclosure of the open-type speaker reaches an equilibrium state. Then, an equilibrium pressure value of the enclosure of the open-type speaker is measured. Then, a judging step is performed to judge whether the open-type speaker has the leak according to a result of comparing the equilibrium pressure value of the open-type speaker with a default negative pressure value. The default negative pressure value is the negative pressure value generated by the vacuum generator when a qualified enclosure is tested.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
In this context, the enclosure (or sound box) of the open-type speaker has an opening. For example, the enclosure used in the open-type speaker of the present invention includes but is not limited to a bass reflex enclosure, a labyrinth enclosure or a horn type enclosure. In the following embodiments, the open-type speaker with the bass reflex enclosure will be illustrated as an example.
When the speaker unit 11 vibrates to generate sound waves, the sound waves may be radiated forwardly toward the front side of the speaker unit 11 and radiated backwardly toward the rear side of the speaker unit 11. The sound wave radiated forwardly toward the front side of the speaker unit 11 is referred as the forwardly-radiated sound wave; and the sound wave radiated backwardly toward the rear side of the speaker unit 11 is referred as the backwardly-radiated sound wave. Generally, the human ear is not very sensitive to the low-frequency sound wave. If the backwardly-radiated sound wave is guided to the outside of the enclosure 12, the low-frequency sound wave is increased. However, the phase of the forwardly-radiated sound wave and the backwardly-radiated sound wave is opposite. If the backwardly-radiated sound wave is directly outputted from the enclosure 12 without being processed, the out-of-phase condition of these two sound waves may result in destructive interference. Under this circumstance, the performance of the speaker 10 is deteriorated. For solving this problem, when the backwardly-radiated sound wave reflected by the backside plate of the enclosure 12 is guided to the opening 13 of the enclosure 12 through the sound guide tube 14, the phase of the backwardly-radiated sound wave is inverted. The inverted phase of the backwardly-radiated sound wave is identical to the phase of the forwardly-radiated sound wave. The backwardly-radiated sound wave with the inverted phase and the forwardly-radiated sound wave are superimposed with each other to result in constructive interference. Under this circumstance, the low-frequency radiation intensity of the open-type speaker 10 is increased. The structure and the operating principle of the open-type speaker 10 are similar to those of the general open-type speaker with the bass reflex enclosure, and are not redundantly described herein.
The sealing element 21 is locked into the opening 13 of the open-type speaker 10 for sealing the opening 13, so that the inner space of the enclosure 12 becomes a sealed space. The sealing element 21 is made of an elastic material. An example of the elastic material includes but is not limited to a rubbery material, a cork material or a plastic material. In this embodiment, the sealing element 21 is a cork stopper, but is not limited thereto. Moreover, the cork stopper 21 comprises a first end A and a second end B. The first end A of the cork stopper 21 is penetrated through the opening 13 and inserted into the inner space of the open-type speaker 10. The second end B of the cork stopper 21 is located outside the open-type speaker 10.
In case that there is a seam between the cork stopper 21 and the opening 13, the opening 13 cannot be sealed by the cork stopper 21 successfully, and the inner space of the open-type speaker 10 cannot be the sealed space. For creating the sealed space, it is preferred that the opening 13 of the open-type speaker 10 is a circular opening and the cork stopper 21 is a cone-shaped structure corresponding to the opening 13. Moreover, the diameter of the first end A of the cork stopper 21 is smaller than the diameter of the opening 13; and the diameter of the second end B of the cork stopper 21 is larger than the diameter of the opening 13. Consequently, the tightness of the cork stopper 21 locked in the opening 13 is increased.
By using the flow of the compressed air, the vacuum generator 22 creates a vacuum. Since the air within the enclosure 12 is extracted out by the vacuum generator 22, a negative pressure in the inner space of the enclosure 12 is generated by the vacuum generator 22. In an embodiment, after the vacuum generator 22 extracts the air of a qualified enclosure for a predetermined time period (e.g. 5 seconds), the value of negative pressure within the qualified enclosure is defined as a default negative pressure value. It is noted that the open-type speaker leak test system is not restricted to generate the negative pressure. Alternatively, in another embodiment of the open-type speaker leak test system, a positive pressure generation device may be used to generate a positive pressure in inner space of the enclosure. According to the positive pressure value, the open-type speaker leak test system may test whether there is a leak.
The first communication tube 23 is in communication with the open-type speaker 10 and the vacuum generator 22. A first end 231 of the first communication tube 23 is penetrated through the sealing element 21 and inserted into the enclosure 12 of the open-type speaker 10. A second end 232 of the first communication tube 23 is connected with the vacuum generator 22.
The components and installations of the pressure measuring module 24 will be illustrated as follows. The pressure measuring module 24 comprises a second communication tube 241 and a pressure gauge 242. The open-type speaker 10 and the second communication tube 241 are in communication with the pressure gauge 242. A first end 243 of the second communication tube 241 is penetrated through the sealing element 21 and inserted into the enclosure 12 of the open-type speaker 10. A second end 244 of the second communication tube 241 is connected with the pressure gauge 242 and located outside the enclosure 12. For example, the pressure gauge 242 is a general barometer for measuring an equilibrium pressure value of the enclosure 12. After the air in the enclosure 12 is extracted by the vacuum generator 22, the air pressure of the enclosure 12 and the air pressure of the first communication tube 23 are gradually in the equilibrium state. Consequently, the inner space of the enclosure 12 has the equilibrium pressure value. Under this circumstance, the equilibrium pressure value of the enclosure 12 can be directly measured by the pressure gauge 242 through the second communication tube 241. Since the influence of the airflow generated during the process of extracting the air by the vacuum generator 22 is minimized, the measured pressure value is more accurate.
In this embodiment, the controller 27 is electrically connected with the pressure gauge 242. The equilibrium pressure value that is measured by the pressure gauge 242 is transmitted to the controller 27. If the equilibrium pressure value is equal to the default negative pressure value, which is the negative pressure generated by the vacuum generator 22 and corresponding to the qualified enclosure, the controller 27 judges that the open-type speaker 10 has no leak. On the other hand, if the absolute value of the equilibrium pressure value is lower than the absolute value of the default negative pressure value, which is the negative pressure generated by the vacuum generator 22 and corresponding to the qualified enclosure, the controller 27 judges that the open-type speaker 10 has a leak.
Moreover, the open-type speaker leak test system 20 is further equipped with the solenoid valve 25 and the pressure stabilizer 26. During the process of testing the open-type speaker 10, the solenoid valve 25 and the pressure stabilizer 26 can control whether the air flows in the first communication tube 23, and can control the airflow in the first communication tube 23 in order to stabilize the air pressure of the first communication tube 23. The solenoid valve 25 and the pressure stabilizer 25 are located at an end of the vacuum generator 22, but are not limited thereto. The solenoid valve 25 is used to control whether the air flows in the first communication tube 23. After the vacuum generator 22 extracts the air from the enclosure 12 for the predetermined time period, the solenoid valve 25 is turned off. Consequently, the vacuum generator 22 no longer extracts the air from the enclosure 12. The pressure stabilizer 26 is used for stabilizing the air pressure of the first communication tube 23. Since the fluctuation amount of the air pressure in the first communication tube 23 is not too large, the read value of the pressure gauge 242 can be easily read. Moreover, for accelerating the testing task, the open-type speaker leak test system is preferably automated. Under this circumstance, the solenoid valve 25 and the pressure stabilizer 26 are electrically connected with the controller 27 and controlled by the controller 27, but are not limited thereto.
Hereinafter, an open-type speaker leak test method according to an embodiment of the present invention will be illustrated with reference to
Firstly, in the step S11, the opening 13 of the open-type speaker 10 is sealed by the sealing element 21, so that an inner space of the enclosure 12 is a sealed space.
In the step S12, the vacuum generator 22 and the pressure measuring module 24 are in communication with the inner space of the enclosure 12 of the open-type speaker 10. As mentioned above, first communication tube 23 is in communication with the vacuum generator 22 and the enclosure 12, and the second communication tube 241 is in communication with the pressure gauge 242 of the pressure measuring module 24 and the enclosure 12.
Then, in the step S13, the vacuum generator 22 is enabled to extract air from the enclosure 12, so that a negative pressure value of the inner space of the enclosure 12 is generated.
Then, the step S14 is performed to wait for an equilibrium state of the air pressure in the vacuum generator 22 and the enclosure 12 of the open-type speaker 10.
When the air pressure reaches the equilibrium state, the equilibrium pressure value of the enclosure 12 of the open-type speaker 10 is measured (Step S15).
Then, the step S16 is performed to judge whether the open-type speaker 10 has the leak according to a result of comparing the equilibrium pressure value of the open-type speaker 10 with a default negative pressure value, wherein the default negative pressure value is a negative pressure generated by the vacuum generator 22 when a qualified enclosure is tested. If the equilibrium pressure value is equal to the default negative pressure value, the controller 27 judges that the open-type speaker 10 has no leak. On the other hand, if the absolute value of the equilibrium pressure value is lower than the absolute value of the default negative pressure value, the controller 27 judges that the open-type speaker 10 has a leak.
In this embodiment, the step of comparing the equilibrium pressure value with the default negative pressure value is performed by the controller 27, which is electrically connected with the pressure gauge 242. It is noted that the step of comparing the equilibrium pressure value with the default negative pressure value is not restricted to be performed by the controller. For example, in some other embodiments, the step of comparing the equilibrium pressure value with the default negative pressure value generated by the vacuum generator may be performed by an inspector.
Hereinafter, an open-type speaker leak test system according to another embodiment of the present invention will be illustrated with reference to
In comparison with the open-type speaker leak test system 20 of
The pressure stabilizing module 321 and the switching element 322 are used for replacing the pressure stabilizer 26 and the solenoid valve 25 of the open-type speaker leak test system 20 of
From the above descriptions, the present invention provides the open-type speaker leak test system and the open-type speaker leak test method. By the vacuum generator, the enclosure of the open-type speaker has a negative pressure value. By the pressure measuring module, the equilibrium pressure value of the enclosure is measured. According to a result of comparing the equilibrium pressure value of the open-type speaker with the default negative pressure value, the open-type speaker leak test system judges whether the open-type speaker has a leak, wherein the default negative pressure value is a negative pressure generated by the vacuum generator when a qualified enclosure is tested. In comparison with the conventional leak test method using the stethoscope, the open-type speaker leak test method of the present invention using the pressure measuring module can reduce the possibility of causing human misjudgment and increase the efficiency of testing the leak of the open-type speaker. Moreover, since the equilibrium pressure value of the inner space of the enclosure is directly measured by the pressure measuring module, the airflow caused by the vacuum generator has less influence on the pressure measuring module. Consequently, the accuracy of measuring the equilibrium pressure value of the inner space of the enclosure will be enhanced.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103121409 | Jun 2014 | TW | national |
