CN105679126B - display device, video system, display method and projector - Google Patents

Abstract

The present invention discloses a display device, a video system, a display method and a projector. The display method is applicable to a display device. The display method comprises: transmitting a preview data output by a client to a host end, so that the host end displays a preview image corresponding to the preview data; and after the host end displays the preview image, if the host end outputs a first display permission signal, the display device displays an image corresponding to an image signal output by the client.

Description

Display device, video system, display method and projector

technical field

The invention relates to a display device, and in particular to a display device capable of providing a preview function, a video system, a corresponding display method and a projector.

Background technique

With the development of information technology, the application of display devices is becoming more and more popular. Common display devices include computer monitors, television monitors, and projectors. Among them, the projector has the advantages of small size, convenient movement, free adjustment of the size of the displayed picture, and the ability to display large-size pictures...etc. Projectors are often used in environments such as teaching, conferences, theaters, etc.

When the projector is used in a teaching environment, for example, the computers of the teacher and multiple students can be connected to the projector at the same time, and the projector can be used to display the images output by the computers of the teacher and the students. However, the images output by the students' computers may contain inappropriate or unsuitable content (such as violent or pornographic content) for public display by the projector. In this way, when the students' computers output inappropriate images to the projector for display, the teaching quality may be affected to a certain extent.

Contents of the invention

An aspect of the present invention is to provide a display device, including a display unit and a processing module. The processing module is electrically connected to the display unit. The processing module is used for sending a preview (preview) data output by the client to a host (host) before the display unit displays an image corresponding to an image signal output by the client (client), for the host Displaying a preview image corresponding to the preview data, wherein the processing module is further used for receiving a first preview request output by the host, and outputting a second preview request to the client according to the first preview request, so that the client receives the first preview request according to the first preview request. The second preview request outputs the preview data to the processing module. The processing module transmits the preview data to the host. After the processing module transmits the preview data to the host, if the processing module receives a first display permission signal output by the host, the processing module is further used to output a second display permission signal to the client according to the first display permission signal terminal, so that the client terminal outputs the image signal to the processing module according to the second display permission signal. The processing module controls the display unit to display a corresponding image according to the image signal.

According to yet another embodiment of the present invention, the preview data includes desktop image snapshot data of the client or real-time desktop image data of the client.

According to yet another embodiment of the present invention, the processing module is further configured to respectively establish wireless connections between the display device and the host and between the display device and the client according to the connection requests sent by the host and the client.

According to another embodiment of the present invention, the above-mentioned display device is a projector.

Another aspect of the present invention is to provide a video system, including a host, at least one client, and a display device. The display device is used for sending a preview data output by the client to a host before displaying an image corresponding to an image signal output by the client, so that the host can display a preview image corresponding to the preview data.

According to an embodiment of the present invention, the display device is further configured to receive a first preview request output from the host, and output a second preview request to the client according to the first preview request, so that the client outputs a preview request according to the second preview request. Preview data to display device. The display device transmits the preview data to the host.

According to another embodiment of the present invention, after receiving the second preview request, the client outputs a preview request message, and outputs preview data to the display device according to a user input command of the client.

According to yet another embodiment of the present invention, after the display device transmits the preview data to the host, if the display device receives a first display permission signal output from the host, the display device is further configured to output a display permission signal according to the first display permission signal. The second display permission signal is sent to the client, so that the client outputs the image signal to the display device according to the second display permission signal. The display device displays corresponding images according to the image signals.

According to yet another embodiment of the present invention, after receiving the preview data, the host terminal displays a preview image according to the preview data, and outputs a first display permission signal to the display device according to a host terminal user command.

According to another embodiment of the present invention, the preview data includes desktop image snapshot data of the client or real-time desktop image data of the client.

According to yet another embodiment of the present invention, the above-mentioned display device is further used to respectively establish wireless connections between the display device and the host and between the display device and the client according to the connection requests sent by the host and the client.

According to yet another embodiment of the present invention, the above-mentioned display device is a projector.

Another aspect of the present invention is to provide a display method suitable for a display device. The display method includes the following steps: sending a preview data output by a client to a host end, so that the host end displays a preview image corresponding to the preview data; and after the host end displays the preview image, if the host end outputs a first A display permission signal is used to display an image corresponding to an image signal output by the client through the display device.

According to an embodiment of the present invention, the above display method further includes: receiving a first preview request output by the host; and outputting a second preview request to the client according to the first preview request, so that the client can Outputting the preview data to a display device.

According to another embodiment of the present invention, in the above display method, after the host end displays the preview image, if the host end outputs the first display permission signal, the display device displays the updated image corresponding to the image signal output by the client end. Including: receiving a first display permission signal, and outputting a second display permission signal to the client according to the first display permission signal, so that the client terminal outputs an image signal according to the second display permission signal; and receiving the image signal, and by The display device displays an image corresponding to the image signal.

According to yet another embodiment of the present invention, the preview data includes desktop image snapshot data of the client or real-time desktop image data of the client.

According to yet another embodiment of the present invention, the above display method further includes: respectively establishing wireless connections between the display device and the host and between the display device and the client according to the connection requests sent by the host and the client.

According to another embodiment of the present invention, the display device is a projector.

Another aspect of the present invention is to provide a projector for transmitting an image data output by a client to a host, so that the host can display an image corresponding to the image data, wherein the projector further uses To receive a first image transmission request output by the host, and output a second image transmission request to the client according to the first image transmission request, so that the client outputs image data to the projector according to the second image transmission request. The projector transmits image data to the host, and the projector is further used to respectively establish wireless connections between the projector and the host and between the projector and the client according to the connection requests sent by the host and the client.

With the technical means of the present invention, the host can preview the image output by the client before the client uses the display device to display the image output by the client. The display device will display the image output by the client after receiving the display permission issued by the host. In this way, the display device can be prevented from displaying that the image output by the client terminal contains inappropriate content. In addition, the present invention enables the host and the client to exchange data through the display device by establishing wireless connections between the display device and the host and between the display device and the client. In this way, the number of connections that need to be established when exchanging data between the host and the client and between the clients can be reduced. Furthermore, the host can receive the image data output by the client through the display device. In this way, the host can receive the image data output by the client without establishing a connection with each client separately.

Description of drawings

FIG. 1A is a schematic block diagram of a display device according to an embodiment of the present invention.

FIG. 1B is a schematic block diagram of a video system according to an embodiment of the present invention.

FIG. 1C is a schematic block diagram of a display device in another embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating operations among a display device, a host terminal, and a client terminal according to another embodiment of the present invention.

FIG. 3 is a schematic flowchart illustrating a display method according to an embodiment of the present invention.

FIG. 4 is a schematic flowchart illustrating a display method according to another embodiment of the present invention.

FIG. 5 is a schematic flowchart illustrating a display method according to another embodiment of the present invention.

Wherein, the reference signs are explained as follows:

100, 100a, 100b: display device

110: display unit

120: processing module

130, 130a, 130b: client

133: Image signal

135: Preview data

140, 140a, 140b: Host side

155: First preview request

157: Second preview request

165: First display permission signal

167: Second display permission signal

175: Image data

185: First image transmission request

187: Second image transmission request

200: Video system

230, 232, 234, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 302, 304, 402, 404, 502: steps

Detailed ways

The following examples are described in detail with reference to the accompanying drawings, but the provided examples are not intended to limit the scope of the present invention, and the description of the structure and operation is not intended to limit the order of its execution, any structure recombined by components, The resulting devices with equivalent functions are within the scope of the present invention. In addition, the drawings are for illustration purposes only and are not drawn to original scale. For ease of understanding, the same components will be described with the same symbols in the following description.

Unless otherwise specified, the terms used throughout the specification and claims generally have the ordinary meaning of each term as used in the art, in this disclosure and in the special context. Certain terms used to describe the present disclosure are discussed below or elsewhere in this specification to provide those skilled in the art with additional guidance in describing the present disclosure.

In addition, as used herein, "coupling" or "connection" may refer to two or more elements being in direct physical or electrical contact with each other, or indirect physical or electrical contact with each other, or referring to two or more components. Multiple elements operate or act on each other.

In this article, "a" and "the" can generally refer to a single or a plurality, unless the article is specifically limited in the context. It will be further understood that "comprises", "comprises", "has" and similar words used herein indicate the features, regions, integers, steps, operations, elements and/or components described therein, but do not exclude One or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof described or additional thereto.

In addition, in this document, it is understandable that terms such as first, second and third are used to describe various elements, components, regions, layers and/or blocks. But these elements, components, regions, layers and/or blocks should not be limited by these terms. These terms are limited to identifying a single element, component, region, layer and/or block. Therefore, a first element, component, region, layer and/or block hereinafter may also be referred to as a second element, component, region, layer and/or block without departing from the spirit of the present invention.

Please refer to Figure 1A. FIG. 1A is a schematic block diagram of a display device 100 according to an embodiment of the present invention. The display device 100 can be a projector or a display, but not limited thereto. The display device 100 includes a display unit 110 and a processing module 120 . In one embodiment, the processing module 120 is a chip. In another embodiment, the display device 100 includes at least one processor and a memory, and the processing module 120 is stored in the memory, and its functions are executed by the processor.

The processing module 120 is electrically connected to the display unit 110 . The processing module 120 is used for sending a preview (preview) data 135 output by the client 130 to a host (host) before the display unit 110 displays an image corresponding to an image signal 133 output by the client 130 ) 140 for the host terminal 140 to display a preview image corresponding to the preview data 135 .

The client 130 and the host 140 can be personal computers, tablet computers, notebook computers, smart phones, etc., but are not limited thereto. In one embodiment, both the client 130 and the host 140 are personal computers, and the display device 100, the client 130, and the host 140 are used in a teaching environment. For example, the user of the host 140 is a teacher, and the user of the client 130 is a student. The processing module 120 is used to transmit the preview data 135 output by the client 130 to the host 140 before the display unit 110 displays the image corresponding to the image signal 133 output by the client 130, so that the teacher can preview the information contained in the preview data 135. corresponding preview image.

In one embodiment, the preview data 135 includes desktop image snapshot data of the client 130 or real-time desktop image data of the client 130 , and the image signal 133 includes real-time desktop image data of the client 130 . Thereby, in the above-mentioned embodiment, before the display unit 110 displays the real-time desktop image of the student's personal computer, the teacher can preview the desktop image snapshot or real-time desktop image data of the student's personal computer. It should be noted that the preview data 135 is not limited to the desktop image snapshot data of the client 130 or the desktop real-time image data of the client 130 , and the image signal 133 is not limited to the desktop real-time image data of the client 130 . In one embodiment, the preview data 135 includes image snapshot data of the application program executed by the client 130 , and the image signal 133 includes real-time image data of the application program executed by the client 130 .

In another embodiment, the processing module 120 is further configured to receive a first preview request 155 output by the host 140 . The processing module 120 outputs a second preview request 157 to the client 130 according to the first preview request 155 , so that the client 130 outputs the preview data 135 to the processing module 120 according to the second preview request 157 . The processing module 120 transmits the preview data 135 to the host 140 . Thereby, in the above-mentioned embodiment, the teacher can use the host terminal 140 to output the first preview request 155 when requesting the students to use the client terminal 130 to output the image corresponding to the image signal 133, so that the client terminal 130 can output according to the second preview request 157. Preview data135.

In yet another embodiment, after the processing module 120 transmits the preview data 135 to the host terminal 140, if the processing module 120 receives a first display permission signal 165 output by the host terminal 140, the processing module 120 is further configured to A display permission signal 165 outputs a second display permission signal 167 to the client 130 , so that the client 130 outputs the image signal 133 to the processing module 120 according to the second display permission signal 167 . The processing module 120 controls the display unit 110 to display a corresponding image according to the image signal 133 . Thereby, in the above-mentioned embodiment, after the host terminal 140 displays the preview image corresponding to the preview data 135 (such as: the desktop image snapshot of the student's personal computer), the teacher can use the host terminal 140 to output the first display permission signal 165, And make the client 130 output the image signal 133 (for example: the real-time image of the desktop of the student's personal computer) to the display device 100 for display according to the second display permission signal 167 . Therefore, the teacher can decide whether to use the host terminal 140 to output the first display permission signal 165 according to the contents of the desktop image snapshot displayed on the host terminal 140 such as the student's personal computer. If the teacher judges that the real-time desktop image of the student's personal computer is not suitable for display by the display device 100 in the teaching environment based on the content of the snapshot of the desktop image of the student's personal computer, the teacher can choose not to use the host terminal 140 to output the first display permission Signal 165. In this way, the display device 100 will not display the real-time image of the desktop of the student's personal computer.

It should be noted that, in this embodiment, the connection between the display device 100 and the host 140 and the connection between the display device 100 and the client 130 may be wired or wireless. In one embodiment, the display device 100 and the host terminal 140 and between the display device 100 and the client terminal 130 are connected wirelessly, and the processing module 120 is further used for connection requests sent by the host terminal 140 and the client terminal 130 , respectively establishing wireless connections between the display device 100 and the host terminal 140 and between the display device 100 and the client terminal 130 . The aforementioned wireless connection may be a WiFi wireless connection, but not limited thereto.

In addition, in this embodiment, the processing module 120 is included in the display device 100 . However, in practical application, the processing module 120 is not limited to be included in the display device 100 . In another embodiment, the processing module 120 is included in other electronic devices, and is electrically connected to the display device 100 (for example, connected via an HDMI interface). In addition, the number of clients and hosts is not limited to one as shown in FIG. 1A . In another embodiment, the display device 100 is wirelessly connected to multiple hosts and multiple clients respectively.

Please refer to Figure 1B. FIG. 1B is a schematic block diagram of a video system 200 according to an embodiment of the present invention. The video system 200 includes a display device 100a, at least one client 130a and a host 140a. The display device 100a, at least one client 130a, and a host 140a can be respectively the display device 100, the client 130, and the host 140 shown in FIG. 1A, but not limited thereto.

The display device 100a is used to transmit a preview data 135 output by at least one client 130a to the host 140a before displaying an image corresponding to an image signal 133 output by at least one client 130a, so that the host 140a can display the preview A preview image corresponding to the data 135 .

In this embodiment, the operations between the display device 100a, the client 130a, and a host 140a are similar to the embodiment shown in FIG. 1A , so details will not be repeated here.

In one embodiment, at least one client 130a outputs a preview request message after receiving the second preview request 157 , and outputs the preview data 135 to the display device 100a according to a command input by a client user. Thus, in the above-mentioned embodiment, after receiving the second preview request 157, the personal computer operated by the student (i.e. the client 130a) outputs a preview request message to ask the student whether to agree to output the preview data 135 (such as: the student's snapshot data of the desktop image of the personal computer), enabling teachers to preview. If the student agrees to output the preview data 135, then the personal computer operated by the student (i.e. the client terminal 130a) outputs the preview data 135 according to the input instruction of the client user (such as the consent instruction input by the student using the keyboard or mouse of the personal computer). to the display device 100a. Conversely, if the student does not agree to output the preview data 135 , the personal computer operated by the student does not output the preview data 135 . In this way, the privacy of students can be better protected.

In another embodiment, after receiving the preview data 135, the host 140a displays a preview image according to the preview data 135, and outputs a first display permission signal 165 to the display device 100a according to a host user command. Thus, in the above-mentioned embodiment, after receiving the preview data 135, the personal computer operated by the teacher (that is, the host terminal 140a) displays a preview image (such as a desktop image snapshot of the student's personal computer) according to the preview data 135 . If the teacher agrees that the personal computer operated by the student (i.e. the client terminal 130a) output the real-time image (i.e. the image signal 133) of the desktop of the student's personal computer to the display device 100a for display after watching the preview image, then the teacher can use the host terminal The keyboard or mouse of 140a generates a host-side user command. The host terminal 140a can output the first display permission signal 165 to the display device 100a according to the above host terminal user instruction.

In the above embodiment, the display device transmits the preview data output by the client to the host before displaying the image corresponding to the image signal output by the client, so that the host can display the preview image corresponding to the preview data. In another embodiment of the present invention, the client can also transmit the image data to the host through the display device. The aforementioned image data is not limited to preview data. An example will be provided below to illustrate the above operations.

Please refer to Figure 1C. FIG. 1C is a schematic block diagram of a display device 100b in another embodiment of the present invention. In FIG. 1C, the display device 100b, the client 130b, and the host 140b can be the display device 100, the client 130, and the host 140 shown in FIG. 1A, respectively, but not limited thereto. In one embodiment, the display device 100b can be a projector or a display, and the client 130b and the host 140b can be personal computers, tablet computers, notebook computers, smart phones, etc.

The display device 100b is used to transmit an image data 175 output by the client 130b to the host 140b, so that the host 140b can display an image corresponding to the image data 175 . It should be noted that, in this embodiment, the image data 175 is not limited to preview data.

In one embodiment, the display device 100b is further configured to receive a first image transmission request 185 output by the host 140b. The display device 100b outputs a second image transmission request 187 to the client 130b according to the first image transmission request 185 , so that the client 130b outputs the image data 175 to the display device 100b according to the second image transmission request 187 . The display device 100b transmits the image data 175 to the host 140b.

In another embodiment, the display device 100b is further used to respectively establish wireless connections between the display device 100b and the host terminal 140b and between the display device 100b and the client 130b according to the connection requests sent by the host terminal 140b and the client 130b. .

In the following, according to another embodiment of the present invention, the operations among the display device, the host terminal, and the client terminal as shown in FIG. 1A and FIG. 1B will be described. Please refer to Figure 2. FIG. 2 is a schematic diagram illustrating operations among a display device, a host terminal, and a client terminal according to another embodiment of the present invention.

In step 230 and step 232, the host and the client respectively output connection requests to the processing module. In step 234, the processing module respectively establishes connections between the display device and the host and between the display device and the client according to the connection requests sent by the host and the client.

In step 240, the host side outputs the first preview request to the processing module. In step 242, the processing module outputs a second preview request to the client according to the first preview request output by the host. In step 244, the client outputs the preview data to the processing module according to the second preview request. In step 246, after receiving the preview data output by the client, the processing module outputs the preview data to the host. Then, in step 248, the host side displays the preview image corresponding to the preview data.

In step 250, the host side outputs a first display permission signal to the processing module. In step 252, the processing module outputs a second display permission signal to the client according to the first display permission signal output by the host. In step 254, the client terminal outputs the image signal to the processing module according to the second display permission signal. Then, in step 256 and step 258, the processing module controls the display unit to display the corresponding image according to the image signal output by the client.

FIG. 3 is a schematic flowchart illustrating a display method according to an embodiment of the present invention. This display method can be applied to the display device 100 as shown in FIG. 1A , but is not limited thereto. For the sake of convenience and clarity, the following description of the display method is described in conjunction with the display device 100 shown in FIG. 1A .

In step 302 , the display device 100 transmits a preview data 135 output by the client 130 to a host 140 for the host 140 to display a preview image corresponding to the preview data 135 .

In step 304 , after the host 140 displays the preview image, if the host 140 outputs a first display permission signal 165 , the display device 100 displays an image corresponding to an image signal 133 output by the client 130 .

Please refer to Figure 4. FIG. 4 is a schematic flowchart illustrating a display method according to an embodiment of the present invention. Compared with the display method shown in FIG. 3 , in this embodiment, the display method further includes step 402 and step 404 . This display method can be applied to the display device 100 as shown in FIG. 1A , but is not limited thereto. For the sake of convenience and clarity, the following description of the display method is described in conjunction with the display device 100 shown in FIG. 1A .

In step 402 , the display device 100 receives a first preview request 155 output from the host 140 .

In step 404 , the display device 100 outputs a second preview request 157 to the client 130 according to the first preview request 155 , so that the client 130 outputs the preview data 135 to the display device 110 according to the second preview request 157 .

Please refer to Figure 5. FIG. 5 is a schematic flowchart illustrating a display method according to an embodiment of the present invention. Compared with the display method shown in FIG. 3 , in this embodiment, the display method further includes step 502 . This display method can be applied to the display device 100 as shown in FIG. 1A , but is not limited thereto. For the sake of convenience and clarity, the following description of the display method is described in conjunction with the display device 100 shown in FIG. 1A .

In step 502 , the display device 100 respectively establishes wireless connections between the display device 100 and the host 140 and between the display device 100 and the client 130 according to the connection requests sent by the host 140 and the client 130 .

It should be understood that, unless the order of the steps mentioned in the above embodiments is specifically stated, the order of the steps may be adjusted according to actual needs, and may even be executed simultaneously or partly simultaneously.

To sum up, with the technical means of the present invention, the host can preview the image output by the client before the client uses the display device to display the image output by the client. The display device will display the image output by the client after receiving the display permission issued by the host. In this way, it is possible to prevent the display device from displaying that the image output by the client contains inappropriate content. In addition, the present invention can establish a wireless connection between the display device and the host and between the display device and the client, so that the host and the client can exchange data through the display device. In this way, the number of connections that need to be established when exchanging data between the host and the client and between the clients can be reduced. Furthermore, the host can receive the image data output by the client through the display device. In this way, the host can receive the image data output by the client without establishing a connection with each client separately.

Although the present disclosure has been disclosed above in terms of implementation, it is not intended to limit the present disclosure, and any person skilled in the art may make various modifications and modifications without departing from the spirit and scope of the present disclosure. , so the protection scope of the present disclosure should be determined by the scope defined by the appended claims.

Claims (17)

1. A display device, characterized in that it comprises: a display unit; and A processing module, electrically connected to the display unit, used for sending a preview data output by the client to a host before the display unit displays an image corresponding to an image signal output by the client end, for the host end to display a preview image corresponding to the preview data, wherein the processing module is also used to receive a first preview request output by the host end, and output a second preview request according to the first preview request A preview request is sent to the client, so that the client outputs the preview data to the processing module according to the second preview request, the processing module sends the preview data to the host, and the processing module sends the preview data to the After the host, if the processing module receives a first display permission signal output by the host, the processing module is also used to output a second display permission signal to the client according to the first display permission signal, so that The client outputs the image signal to the processing module according to the second display permission signal, and the processing module controls the display unit to display a corresponding image according to the image signal. 2. The display device as claimed in claim 1, wherein the preview data comprises snapshot data of the desktop image of the client or real-time desktop image data of the client. 3. The display device as claimed in claim 1, wherein the processing module is further configured to respectively establish connections between the display device and the host and between the display device and the client according to connection requests sent by the host and the client. Wireless connection between clients. 4. The display device as claimed in claim 1, wherein the display device is a projector. 5. A video system, characterized in that, comprising: a host terminal; at least one client; and A display device, used to transmit a preview data output by the at least one client to a host end before displaying an image corresponding to an image signal output by the at least one client end, so that the host end can display the preview a preview image corresponding to the data; Wherein the display device is also used for receiving a first preview request output by the host terminal, and outputting a second preview request to the at least one client according to the first preview request, so that the at least one client receives the first preview request according to the first preview request. A preview request outputs the preview data to the display device, and the display device transmits the preview data to the host. 6. The video system as claimed in claim 5, wherein the at least one client terminal outputs a preview request message after receiving the second preview request, and outputs the preview data to the display device. 7. The video system according to claim 5, wherein after the display device transmits the preview data to the host, if the display device receives a first display permission signal output by the host, the display device It is also used to output a second display permission signal to the at least one client according to the first display permission signal, so that the at least one client terminal outputs the image signal to the display device according to the second display permission signal, and the display device according to The image signal displays a corresponding image. 8. The video system as claimed in claim 7, wherein the host terminal displays a preview image according to the preview data after receiving the preview data, and outputs the first display permission signal to The display device. 9. The video system as claimed in claim 5, wherein the preview data comprises snapshot data of the client's desktop image or real-time desktop image data of the client. 10. The video system as claimed in claim 5 , wherein the display device is further used to respectively establish connections between the display device and the host terminal and the display device according to connection requests sent by the host terminal and the at least one client terminal. A wireless connection with the at least one client. 11. The video system of claim 5, wherein the display device is a projector. 12. A display method, suitable for a display device, characterized in that the display method comprises: sending a preview data output by a client to a host, so that the host can display a preview image corresponding to the preview data; and After the host end displays the preview image, if the host end outputs a first display permission signal, the display device displays an image corresponding to an image signal output by the client end; Among them, the display method also includes: receiving a first preview request output by the host; and Outputting a second preview request to the client according to the first preview request, so that the client outputs the preview data to the display device according to the second preview request. 13. The display method according to claim 12, wherein after the host terminal displays the preview image, if the host terminal outputs the first display permission signal, the display device displays the image output by the client terminal The image corresponding to the signal also includes: receiving the first display permission signal, and outputting a second display permission signal to the client according to the first display permission signal, so that the client terminal outputs the image signal according to the second display permission signal; and The image signal is received, and the image corresponding to the image signal is displayed by the display device. 14. The display method as claimed in claim 12, wherein the preview data comprises snapshot data of the desktop image of the client or real-time desktop image data of the client. 15. The display method according to claim 12, further comprising: According to the connection requests sent by the host and the client, the wireless connections between the display device and the host and between the display device and the client are respectively established. 16. The display method as claimed in claim 12, wherein the display device is a projector. 17. A projector, used to transmit an image data output by a client to a host, so that the host can display an image corresponding to the image data, characterized in that the projector is also used to receive The host terminal outputs a first image transmission request, and outputs a second image transmission request to the client according to the first image transmission request, so that the client outputs the image data to the client according to the second image transmission request. The projector, the projector transmits the image data to the host end, and the projector is also used to establish connections between the projector and the host end and the connection requests sent by the host end and the client end respectively. The wireless connection between the projector and the client.