Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The application aims to provide a multimedia playing control scheme suitable for double-screen or multi-screen terminal equipment, so that a user can control multimedia played by different screens of the terminal equipment more conveniently.
On one hand, the embodiment of the application provides a multimedia playing control method, which is applied to terminal equipment with a first screen and a second screen. It should be understood that the electronic device of the embodiment of the present application is not limited to having only the first screen and the second screen, but may also have a plurality of screens, for example: third screen … … screen N. The screens may be formed by folding a flexible screen.
As shown in fig. 1, the play control method includes:
step S102, displaying a playing interface of a first multimedia on a first screen, and displaying a playing interface of a second multimedia on a second screen.
For step S102:
after the playing interfaces of the first multimedia and the second multimedia are displayed, the first multimedia and the second multimedia can be operated by the foreground of the terminal equipment and can also be operated by the background of the terminal equipment.
Step S104, receiving a first input through the target screen.
For step S104:
the target screen may be the first screen or the second screen on the terminal device, or may be another screen on the terminal device, such as the third screen … … nth screen.
And step S106, responding to the first input received by the target screen, and displaying a play control menu aiming at the first multimedia and the second multimedia on the target screen.
For step S106:
the multimedia play control menu is used for controlling the playing of the multimedia, and may be, but is not limited to, provided with at least one play control function of fast forward, rewind, pause, volume up, volume down, and the like.
And receiving the selection operation of the user for the first target function option in the play control menu, and controlling the terminal equipment to execute the first target function in response to the selection operation for the first target function option in the play control menu. E.g., the user selects the fast forward function option, the first multimedia and/or the second multimedia are controlled to play fast forward.
It should be understood that the playing control menus of the first multimedia and the second multimedia are displayed on the target screen, so that the user can respectively control the multimedia played by the first screen and the second screen through the target screen.
The multimedia playing control menu may include a first playing control menu for controlling playing of the first multimedia and a second playing control menu for controlling playing of the second multimedia. For example, the user selects the fast forward function option in the first play control menu, and controls the first multimedia to fast forward play. For example, the user selects the fast forward function option in the second play control menu, and controls the second multimedia to fast forward play.
The multimedia playing control menu may further include a third playing control menu, where the third playing control menu is used to control the playing of the first multimedia and the playing of the second multimedia at the same time, receive a selection operation of a user for a second target function option in the third playing control menu, and control the terminal device to execute a second target function in response to the selection operation for the second target function option in the third playing control menu. For example, the user selects the fast forward function option, the first multimedia and the second multimedia are controlled to be fast forward played.
According to the playing control method, the terminal device is provided with the at least two screens, and a user can initiate an operation request to any one screen in the terminal device to call the playing control menu of the multimedia corresponding to the at least two screens, so that the multimedia played by different screens can be controlled more conveniently, and the use experience is improved.
The following describes the playback control method according to the embodiment of the present application in detail.
Specifically, the play control menu according to the embodiment of the application can be displayed on the status bar of the terminal device, so that the user can conveniently and quickly call the play control menu.
That is, the first input may include: and displaying the status bar input. Correspondingly, step S104 specifically includes:
in step S1041, a status bar is displayed on the target screen.
Step S1042, displaying a play control menu for the first multimedia and a play control menu for the second multimedia in the display area of the status bar.
By way of exemplary introduction, assuming that the play control method according to the embodiment of the present application is used for performing multimedia control on a first screen and a second screen of a terminal device, a status bar may be as shown in fig. 2, where a display area on the left half displays a play control menu of a first multimedia, and a display area on the right half displays a play control menu of a second multimedia.
The user can respectively control the playing of the first multimedia played by the first screen and the second multimedia played by the second screen through the playing control menu in the status bar, such as mute playing, pause playing, playing of the next set and the like.
Meanwhile, the user can also perform a sliding operation on the multimedia play control menu as shown in the direction of fig. 2. For example, the first multimedia is slid down in the area of the play control menu of the first multimedia to reduce the play volume of the first multimedia; for another example, the second multimedia is slid to the right in the area of the play control menu of the second multimedia to fast forward the play progress of the second multimedia.
It should be understood that in practical applications, the target multimedia may be songs, videos, pictures, etc. containing audio data and/or image data. In order to realize more application scenarios, the play control method of the embodiment of the present application may separately control the image data and the audio data of the multimedia.
For controlling the image data, after step S104, the playing control method according to the embodiment of the present application may further include:
step S105, receiving a second input of the play control menu for the target multimedia, where the target multimedia includes the first multimedia or the second multimedia.
Step S106, in response to the second input, displaying the image data included in the control target multimedia only on the first screen, or displaying the image data included in the control target multimedia only on the second screen, or displaying the image data included in the control target multimedia on the first screen and the second screen.
By way of exemplary introduction, as shown in fig. 3, an embodiment of the present application may provide three image playing configurations of a target multimedia to a user in a display area of a playing control menu of the target multimedia, including:
the image playing configuration 1 is used for starting the independent playing of a first screen;
the image playing configuration 2 is used for starting the independent playing of the second screen;
and 3, image playing configuration 3, which starts the synchronous playing of the two screens.
The user can select a target image playing configuration from the three image playing configurations according to the playing requirements, so that the first screen and/or the second screen are controlled to play the image data of the target multimedia according to the target image playing configuration.
For controlling the audio data, after step S104, the playing control method according to the embodiment of the present application may further include:
step S107, a third input of the play control menu for the target multimedia is received.
Step S108, responding to the third input, controlling the audio data included in the target multimedia to be played through the audio channel (such as a wireless audio channel, a wired audio channel, etc.) corresponding to the first screen, or controlling the audio data included in the target multimedia to be played through the audio channel corresponding to the second screen, or controlling the audio data included in the target multimedia to be played through the audio channel corresponding to the first screen and the audio channel corresponding to the second screen;
by way of exemplary introduction, assuming that a first screen corresponds to a first audio channel and a second screen corresponds to a second audio channel, as shown in fig. 4, the embodiment of the present application may provide three audio playing configurations of the target multimedia to the user in a display area of a playing control menu of the target multimedia, including:
audio playing configuration 1, starting the first audio channel to play independently;
audio playing configuration 2, which starts the second audio channel to play independently;
and 3, audio playing configuration, namely starting two audio channels to play synchronously.
Similarly, the user can select a target audio playing configuration from the three audio playing configurations according to the playing requirement, so as to control the audio channels corresponding to the first screen and/or the second screen to play the audio data of the target multimedia according to the target image playing configuration.
It should be understood that, in the embodiments of the present application, a plurality of play rules can be implemented by separately controlling the image data and the audio data of the multimedia.
Such as:
and controlling the target multimedia to be played only on the first screen according to the first playing rule.
The target multimedia can be set according to fig. 5 for the play control menu of the first play rule, and the user selects an option of "start the first screen independent play" in the image play configuration and an option of "start the first audio channel independent play" in the audio play configuration.
Based on the first playing rule, the user controls the target multimedia to be played only on the first screen based on the playing control menu, and the second screen can process other tasks. For example, while a user is watching a movie through the first screen, the user can also browse a web page through the second screen. For another example, a user corresponding to the first screen may watch a television play through the first screen, and a user corresponding to the second screen may work through the second screen.
And a second playing rule is that the target multimedia is controlled to be played synchronously on the first screen and the second screen, and only the sound of the second audio channel is started.
The play control menu of the target multimedia for the second play rule may be set according to fig. 6, and the user selects an option of "start two screens to play synchronously" in the image play configuration and an option of "start a second audio channel to play independently" in the audio play configuration (the second audio channel corresponds to the second screen).
Based on the second playing rule, the user of the first screen and the user of the second screen can synchronously watch the content of the target multimedia only.
And a third playing rule is that the target multimedia is controlled to be asynchronously played on the first screen and the second screen.
The target multimedia can be set according to fig. 7 for the play control menu of the third play rule, and the user selects two options of "start the first screen independent play" and "start the second screen independent play" in the image play configuration, and two options of "start the first audio channel independent play" and "start the second audio channel independent play" in the audio play configuration.
Based on the third playing rule, the user of the first screen and the user of the second screen can play the target multimedia according to respective requirements without mutual interference,
And a fourth playing rule, wherein the target multimedia 1 is controlled to be played on the first screen, and the target multimedia 2 is controlled to be played on the second screen.
The play control menu of the target multimedia 1 for the play rule four and the play control menu of the target multimedia 2 for the play rule four may be set according to fig. 8. A user selects an option of 'starting first screen independent playing' of image playing configuration and an option of 'starting first audio channel independent playing' in audio playing configuration from a playing control menu corresponding to the target multimedia 1; at the same time, the user selects the option of 'starting the independent playing of the second screen' of the image playing configuration in the playing control menu corresponding to the target multimedia 2
Based on the fifth playing rule, the user of the first screen and the user of the second screen can play different target multimedia without interfering with each other.
And a fifth playing rule: the target multimedia is set to be played on the first screen, and the second screen synchronizes only the audio data of the target multimedia.
The target multimedia can be set according to fig. 7 for the play control menu of the fifth play rule, and the user selects an option of "start the first screen independent play" in the image play configuration and an option of "start the two audio channels synchronous play" in the audio play configuration.
Based on the fifth playing rule, the user of the first screen and the user of the second screen want to watch the target multimedia together, but when the user of the second screen needs to use other APPs through the second screen, the first screen can be controlled to normally play the target multimedia, and the second screen only synchronizes the audio data of the target multimedia played by the first screen, so as to avoid restricting the user of the second screen.
Therefore, the play control method based on the embodiment of the application can meet application scenes with different play requirements, such as:
1) when a child needs to watch videos, an adult needs to check other information through the double-sided screen mobile terminal, the terminal equipment can be fixed on a certain support, one screen is used for the child to watch the videos, and the other screen is used for the adult to inquire other operations;
2) when a plurality of people want to watch the same video at the same time, the same video can be put on two screens of the terminal equipment according to the requirement, so that the requirement that a plurality of people share the same video is met;
3) when two people want to watch different video resources, different video contents can be put on different screens of the terminal equipment for watching, respective audio channels are separately output, and a watcher can acquire audio information through the earphone peripheral equipment to meet the requirements of watching different videos of the user.
4) When two people want to play different music at the same time, the music can be played through different audio channels respectively, and the requirement that users listen to the respective music is met.
In addition, in the embodiment of the application, the user can also close the playing of the first multimedia and/or close the playing of the second multimedia through the status bar displayed on the target screen.
Namely, the play control method further includes:
in step S109, a fourth input to the status bar is received.
Step S110, in response to a fourth input, closing the playing of the first multimedia, or closing the playing of the second multimedia, or closing the playing of the first multimedia and the second multimedia.
As an exemplary introduction, a user may select and drag a play control menu of multimedia currently played on any screen in a status bar through touch operation, and when a dragging example reaches a preset threshold, a closing request for the multimedia corresponding to the play control menu is triggered.
In addition, the playing control method of the embodiment of the application can also display the playing control menu of the target media after identifying the playing request of the user for the target multimedia, so that the user configures the playing rule of the target multimedia and plays the target multimedia based on the playing control menu of the target media.
For example, after the user initiates a play input for the first multimedia through the first screen, the play control menu for the first multimedia can be displayed on the first screen. And then, before the first multimedia is played, the user configures the playing rule through the playing control menu of the first multimedia. After the configuration is completed, the first multimedia can be controlled to be played on the terminal equipment according to the configured playing rule.
In addition, the play control method of the embodiment of the application may also modify the play rule of the target multimedia in the play process of the target multimedia.
Namely, after receiving the configuration modification input aiming at the playing interface of the target multimedia, displaying the playing control menu of the target multimedia on the playing interface of the target multimedia; and then, the user can configure the playing rule of the target multimedia and play the target multimedia according to the playing control menu displayed on the playing interface of the target multimedia.
For example, when the user corresponding to the first screen uses the first screen to play the target multimedia and the user corresponding to the second screen uses the second screen to do other things, the user corresponding to the first screen may display the play control menu of the target multimedia by touching the designated area of the play interface of the target multimedia. And then, the user corresponding to the first screen controls the target multimedia to be played on the second screen based on the playing control menu of the target multimedia, so that the target multimedia is shared to the user of the second screen. After the sharing is finished, the user corresponding to the first screen can also close the target multimedia to play on the second screen based on the playing control menu of the target multimedia.
The foregoing is an exemplary description of the playback control method according to the embodiment of the present application, and suitable changes may be made without departing from the principles described herein.
Correspondingly, as shown in fig. 10, an embodiment of the present application further provides a multimedia playback control apparatus 1000, which is applied to a terminal device having a first screen and a second screen. The playback control apparatus 1000 includes:
the processing module 1001 is configured to display a playing interface of a first multimedia on a first screen, and display a playing interface of a second multimedia on a second screen.
The first receiving module 1002 is configured to receive a first input through a target screen.
A first response module 1003, configured to display, on a target screen, a play control menu for the first multimedia and the second multimedia in response to the first input.
In the play control device in the embodiment of the application, the terminal device has at least two screens, and the user can initiate an operation request to any one screen in the terminal device to take out the play control menu of the multimedia corresponding to each of the at least two screens, so that the multimedia played by different screens can be controlled more conveniently, and the use experience is improved.
Optionally, the first input comprises a display status bar input; the first display module is specifically configured to display a status bar on a target screen, and display a play control menu for the first multimedia and a play control menu for the second multimedia in a display area of the status bar.
Optionally, the play control apparatus according to this embodiment of the present application further includes:
and the second receiving module is used for receiving a second input aiming at the playing control menu of the target multimedia after the playing control menus aiming at the first multimedia and the second multimedia are displayed on the target screen.
And the first execution module is used for responding to the second input, controlling the image data included by the target multimedia to be displayed only on the first screen, or controlling the image data included by the target multimedia to be displayed only on the second screen, or controlling the image data included by the target multimedia to be displayed on the first screen and the second screen.
Wherein the target multimedia includes the first multimedia or the second multimedia.
Optionally, the play control apparatus according to this embodiment of the present application further includes:
and a third receiving module, configured to receive a third input of the play control menu for the target multimedia after the play control menus for the first multimedia and the second multimedia are displayed on the target screen.
And the second execution module responds to the third input, controls the audio data included by the target multimedia to be played through the audio channel corresponding to the first screen, or controls the audio data included by the target multimedia to be played through the audio channel corresponding to the second screen, or controls the audio data included by the target multimedia to be played through the audio channel corresponding to the first screen and the audio channel corresponding to the second screen.
Wherein the target multimedia includes the first multimedia or the second multimedia.
Optionally, the play control apparatus according to this embodiment of the present application further includes:
a fourth receiving module for receiving a fourth input for the status bar.
And the third execution module is used for responding to the fourth input, and closing the playing of the first multimedia, or closing the playing of the second multimedia, or closing the playing of the first multimedia and the second multimedia.
Obviously, the playback control apparatus according to the embodiment of the present application is used as the execution main body of the playback control method shown in fig. 1, and therefore, the functions that can be realized by the playback control method in fig. 1 to 9 can also be realized by the playback control apparatus according to the embodiment of the present application, and are not described herein again.
In addition, as shown in fig. 11, an embodiment of the present application further provides a terminal device 1100, where the terminal device 1100 includes, but is not limited to: radio frequency unit 1101, network module 1102, audio output unit 1103, input unit 1104, sensor 1105, display unit 1106, user input unit 1107, interface unit 1108, memory 1109, processor 1110, and power supply 1111. Those skilled in the art will appreciate that the terminal structure shown in fig. 11 does not constitute a limitation of terminal device 1100, and terminal device 1100 may include more or fewer components than shown, or some components may be combined, or a different arrangement of components. In the embodiment of the present application, the terminal device 1100 includes, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a palm computer, a vehicle-mounted terminal, a wearable device, a pedometer, and the like.
Wherein, the processor 1110 is configured to:
and displaying a playing interface of the first multimedia on the first screen, and displaying a playing interface of the second multimedia on the second screen.
A first input is received through a target screen.
Displaying a play control menu for the first multimedia and the second multimedia on a target screen in response to the first input received by the target screen.
And displaying a playing control menu aiming at the first multimedia and the second multimedia on a screen.
The terminal equipment provided by the embodiment of the application is provided with the at least two screens, and a user can initiate an operation request to any one screen in the terminal equipment to call out the playing control menu of the multimedia corresponding to the at least two screens, so that the multimedia played by different screens can be controlled more conveniently, and the use experience is improved.
It should be understood that, in the embodiment of the present application, the radio frequency unit 1101 may be configured to receive and transmit signals during a message transmission or a call, and specifically, receive downlink data from a base station and then process the received downlink data to the processor 1110; in addition, the uplink data is transmitted to the base station. In general, radio frequency unit 1101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit 1101 may also communicate with a network and other devices through a wireless communication system.
The terminal device 1100 provides the user with wireless broadband internet access via the network module 1102, such as assisting the user in e-mailing, browsing web pages, and accessing streaming media.
The audio output unit 1103 may convert audio data received by the radio frequency unit 1101 or the network module 1102 or stored in the memory 1109 into an audio signal and output as sound. Also, the audio output unit 1103 may also provide audio output related to a specific function performed by the terminal 1100 (e.g., a call signal reception sound, a message reception sound, etc.). The audio output unit 1103 includes a speaker, a buzzer, a receiver, and the like.
The input unit 1104 is used to receive audio or video signals. The input Unit 1104 may include a Graphics Processing Unit (GPU) 11041 and a microphone 11042, and the Graphics processor 11041 processes image data of still pictures or video obtained by an image capturing apparatus (e.g., a camera) in a video capturing mode or an image capturing mode. The processed image frames may be displayed on the display unit 1106. The image frames processed by the graphic processor 11041 may be stored in the memory 1109 (or other storage medium) or transmitted via the radio frequency unit 1101 or the network module 1102. The microphone 11042 may receive sound and can process such sound into audio data. The processed audio data may be converted into a format output transmittable to a mobile communication base station via the radio frequency unit 1101 in case of the phone call mode.
Terminal device 1100 also includes at least one sensor 1105, such as a light sensor, motion sensor, and other sensors. Specifically, the light sensor includes an ambient light sensor that adjusts the brightness of the display panel 11061 according to the brightness of ambient light, and a proximity sensor that turns off the display panel 11061 and/or the backlight when the terminal device 1100 moves to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in each direction (generally three axes), detect the magnitude and direction of gravity when stationary, and can be used to identify the terminal posture (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration identification related functions (such as pedometer, tapping), and the like; the sensors 1105 may also include fingerprint sensors, pressure sensors, iris sensors, molecular sensors, gyroscopes, barometers, hygrometers, thermometers, infrared sensors, etc., and will not be described in detail herein.
The display unit 1106 is used to display information input by a user or information provided to the user. The Display unit 1106 may include a Display panel 11061, and the Display panel 11061 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-emitting Diode (OLED), or the like.
The user input unit 1107 is operable to receive input numeric or character information and generate key signal inputs relating to user settings and function control of the terminal device. Specifically, the user input unit 1107 includes a touch panel 11071 and other input devices 11072. The touch panel 11071, also referred to as a touch screen, may collect touch operations by a user on or near the touch panel 11071 (e.g., operations by a user on or near the touch panel 11071 using a finger, a stylus, or any other suitable object or attachment). The touch panel 11071 may include two portions of a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, and sends the touch point coordinates to the processor 1110, and receives and executes commands sent from the processor 1110. In addition, the touch panel 11071 may be implemented by various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. The user input unit 1107 may include other input devices 11072 in addition to the touch panel 11071. In particular, the other input devices 11072 may include, but are not limited to, a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which are not described in detail herein.
Further, the touch panel 11071 can be overlaid on the display panel 11061, and when the touch panel 11071 detects a touch operation thereon or nearby, the touch operation is transmitted to the processor 1110 to determine the type of the touch event, and then the processor 1110 provides a corresponding visual output on the display panel 11061 according to the type of the touch event. Although the touch panel 11071 and the display panel 11061 are shown in fig. 11 as two separate components to implement the input and output functions of the terminal, in some embodiments, the touch panel 11071 and the display panel 11061 may be integrated to implement the input and output functions of the terminal, and the implementation is not limited herein.
The interface unit 1108 is an interface for connecting an external device to the terminal apparatus 1100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device having an identification module, an audio input/output (I/O) port, a video I/O port, an earphone port, and the like. Interface unit 1108 may be used to receive input (e.g., data information, power, etc.) from external devices and transmit the received input to one or more elements within terminal apparatus 1100 or may be used to transmit data between terminal 1100 and external devices.
The memory 1109 may be used to store software programs as well as various data. The memory 1109 may mainly include a storage program area and a storage data area, where the storage program area may store an operating system, an application program (such as a sound playing function, an image playing function, etc.) required by at least one function, and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. In addition, the memory 1109 may include high speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
The processor 1110 is a control center of the terminal, connects various parts of the entire terminal using various interfaces and lines, and performs various functions of the terminal and processes data by operating or executing software programs and/or modules stored in the memory 1109 and calling data stored in the memory 1109, thereby integrally monitoring the terminal. Processor 1110 may include one or more processing units; preferably, the processor 1110 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 1110.
Terminal device 1100 can also include a power supply 1111 (e.g., a battery) for powering the various components, and preferably, the power supply 1111 can be logically coupled to the processor 1110 via a power management system that provides functionality for managing charging, discharging, and power consumption.
In addition, the terminal device 1100 includes some functional modules that are not shown, and are not described in detail herein.
In addition, the terminal device 1100 may also execute the play control method shown in fig. 1, and implement the functions of the play control apparatus in the embodiments shown in fig. 1 to 9, which are not described herein again.
In addition, an embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the computer program implements each process of the method embodiment in fig. 1, and can achieve the same technical effect, and in order to avoid repetition, details are not repeated here. The computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.
It should be understood that, when being executed by a processor, a computer program in a computer-readable storage medium according to an embodiment of the present application can implement the functions of the playback control apparatus in the embodiments shown in fig. 1 to 9, which are not described herein again.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present application.
While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.