JPH11215175A - Document information transmitting system and document information transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily transmit document information composed of characters or pictures at a high speed by eliminating the time require for printing the document information on a form. SOLUTION: In a document information transmitting system 100, a transmitter 200 repeatedly transmits document information composed of characters or pictures. When the transmitter 200 transmits the document information, the data transmitting rate of the document information is suitably switch to a high-speed mode or low-speed mode. A viewer 300 receives the transmitted document information one-page amount by one-page amount and displays the information on a displaying section. The viewer 300 makes receiving operations after discriminating the data transmission mode, whether the high-speed mode or low-speed mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting apparatus for transmitting document information composed of characters or images created by a personal computer or the like, and receiving the document information transmitted from the transmitting apparatus and displaying the document information on a display unit. And a receiving device for displaying. Further, the present invention relates to an information transmitting apparatus for transmitting information such as the document.

[0002]

2. Description of the Related Art To transmit document information composed of characters or images to another person, it is common to record the characters or images on a sheet and distribute the sheet to another person. For example, when holding a meeting, the person in charge creates a document describing the contents of the meeting and a document describing the graph using a personal computer or the like, prints the document on a sheet, and uses the sheet as a meeting material to participate in the meeting. Distributed to the public. Thereby, the contents of the conference can be transmitted to the participants of the conference.

[0003] In addition, participants of a conference prepare personal computers at the time of the conference, obtain a data file of the document information, and display the data file on a display. Can be communicated to conference participants.

[0004]

However, as described above, in the method of transmitting document information via paper,
Since a document created by a personal computer or the like must be printed on paper, there is a problem that it is troublesome and complicated. For example, if you have a large number of conference participants,
After duplicating a number of meeting materials, you can print, edit,
There is a problem that labor, time and labor spent on sorting and the like are large.

On the other hand, even if each participant in the conference can prepare a personal computer for displaying the document information, the data file of the document information is distributed in advance on a floppy disk or the like, In addition to the trouble of transmitting the data via the network, the burden on the equipment is increased.

[0006] By the way, instead of handing over the meeting materials in advance in the form of a printed matter, a data file or the like to the attendees of the meeting in advance, the document information is wirelessly transmitted during the meeting and transmitted via a wireless modem or the like. If the data can be displayed on the personal computer of each participant in real time, the labor is reduced and it is convenient for the participants of the conference.

However, even in this case, if there are many participants in the conference, it may be difficult to prepare a large number of personal computers or the cost may be high. Furthermore, as a result of restricting the transmission speed to maintain the quality of wireless transmission, if there is a large amount of document information, it may take time to display it. On the other hand, if the transmission speed of wireless transmission is increased, transmission errors are likely to occur.
There is an adverse effect such as that part of the transmitted document information is missing. As a result, there is a problem that the efficiency of the conference may be reduced as a whole.

Accordingly, the present invention has been made in view of the above-described problems, and has as its object to eliminate the trouble of printing document information consisting of characters or images on paper and to realize the transmission of document information easily and inexpensively. It is an object of the present invention to provide a document information transmission system and a document information transmission device capable of quickly displaying a document by high-speed wireless transmission while maintaining a certain level of wireless transmission quality.

[0009]

According to one aspect of the present invention, there is provided a document information transmission system for transmitting document information in which characters or images are recorded in page units, and a transmission apparatus for transmitting the document information. A document information transmission system, comprising: a reception device that receives and displays document information transmitted from the device, wherein the transmission device repeatedly transmits document information including a plurality of pages at a set transmission speed. And transmission control means for controlling a transmission operation of the transmission means by switching between two or more modes for respectively setting different transmission speeds, wherein the receiving device comprises at least one of the plurality of pages of document information. Specifying means for specifying one page of document information; and at least the specified at least one of the plurality of pages of document information transmitted by the transmitting means. Receiving means for receiving one page of document information, a display unit having a display area capable of simultaneously displaying the at least one page of document information, and display means for displaying the received document information on the display unit It is characterized by having.

According to the first aspect of the present invention, in the transmission device, the transmission speed of the document information including a plurality of pages is set by the transmission control means by switching the mode. Then, the document information is repeatedly transmitted at the set transmission speed by the transmission means.

In the receiving device, at least one page of document information specified by the specifying means is received by the receiving means at the transmitted transmission speed. Then, at least one page of the received document information is simultaneously displayed on the display area of the display unit by the display means.

Therefore, when transmitting document information, by switching a plurality of transmission speeds and setting them appropriately according to the situation, it is possible to prioritize high-speed display at the receiving device, or prioritize certainty of data transmission. Enables selection of an appropriate transmission method.

A document information transmission system according to a second aspect is the document information transmission system according to the first aspect,
The transmitting means and the receiving means perform radio transmission / reception by a spread spectrum method based on a direct spreading method, and the transmission control means includes a low speed mode having a long spreading code length and a low transmission speed, and a low spreading mode having a short spreading code length and a short transmission speed. The transmission operation of the transmission means is controlled by switching between a high-speed mode and a high-speed mode.

According to the second aspect of the present invention, the transmission of the document information from the transmitting means to the receiving means is performed by a direct spread method which is a kind of the spread spectrum method. Then, switching between two modes, a low-speed mode using a long spreading code length and a high-speed mode using a short spreading code length, is controlled.

Therefore, when transmitting document information, the high-speed mode is set when priority is given to high-speed display at the receiving device, and when priority is given to the reliability of data transmission, the processing gain is increased with respect to the same occupied band. It is possible to select an appropriate transmission method by setting a low-speed mode in which the error rate is reduced.

According to a third aspect of the present invention, in the document information transmission system according to the first or second aspect, the transmission control means switches the mode according to a preset timing, 4. The transmission operation of said transmission means is controlled.
According to the invention described in (1), the mode for setting the transmission speed of the document information is switched by the transmission control means in accordance with a preset timing.

Therefore, when transmitting the document information, it can be determined that the document information is transmitted in an appropriate mode, for example, in the order of transmission pages, and it is possible to perform appropriate transmission according to the contents of the document information.

According to a fourth aspect of the present invention, in the document information transmission system according to any one of the first to third aspects, the receiving device transmits the received document information in any of the modes. Determining means for determining whether or not the receiving operation is performed by the receiving means based on the determination result.

According to the present invention, when the receiving apparatus receives the document information, the type of the mode is determined by the determining means. Then, a receiving operation is performed by the receiving means according to the result of the determination.

Therefore, the receiving apparatus can recognize in what mode the transmitted document information is transmitted, and appropriate reception control can be performed according to the mode.

According to a fifth aspect of the present invention, in the document information transmission system, the transmitting unit transmits mode information indicating a setting state of the two or more modes in addition to the document information, and the receiving unit transmits the mode information. The information is received, and the determination unit makes a determination according to the reception result.

According to the fifth aspect of the present invention, when the document information is transmitted by the transmission means, the mode setting state is transmitted as mode information. The receiving device receives the mode information together with the document information, the type of the mode is determined by the determining unit, and the receiving operation is performed by the receiving unit according to the result.

Therefore, the transmission device can notify the receiving device of the mode in which the transmitted document information was transmitted, and appropriate transmission control can be performed according to the mode. Becomes

According to a sixth aspect of the present invention, there is provided a document information transmitting apparatus for transmitting document information in which characters or images are recorded in page units. It is characterized by comprising transmission means for repeatedly transmitting data according to the transmission rate, and transmission control means for controlling the transmission operation of the transmission means by switching between two or more modes for setting different transmission rates.

According to the invention described in claim 6, the transmission speed of the document information composed of a plurality of pages is set by the transmission control means by switching the mode. Then, the document information is repeatedly transmitted at the set transmission speed by the transmission means.

Therefore, when transmitting the document information to the receiving device, by switching a plurality of transmission speeds and appropriately setting the transmission speed according to the situation, it is possible to give priority to the high-speed display on the receiving device side or to ensure the data transmission. For example, it is possible to select an appropriate transmission method such as giving priority to

According to a seventh aspect of the present invention, in the document information transmitting apparatus according to the sixth aspect, the transmitting means performs wireless transmission by a spread spectrum method based on a direct spread method and controls the transmission control. The means controls the transmission operation of the transmitting means by switching between a low-speed mode having a long spreading code length and a low transmission speed and a high-speed mode having a short spreading code length and a high transmission speed.

According to the seventh aspect of the present invention, the transmission of the document information by the transmission means is performed by a direct spread system, which is one of the spread spectrum systems. Then, switching between two modes, a low-speed mode using a long spreading code length and a high-speed mode using a short spreading code length, is controlled.

Therefore, when transmitting the document information to the receiving apparatus, the high-speed mode is set when priority is given to the high-speed display on the receiving apparatus side, and when the reliability of data transmission is prioritized, the same occupied band is set. By setting the low-speed mode that can increase the processing gain and reduce the error rate,
Enables selection of an appropriate transmission method.

The document information transmitting device according to claim 8 is the document information transmitting device according to claim 6 or 7, wherein the transmitting means sets the two or more modes in addition to the document information. It is characterized by transmitting mode information indicating a state.

According to the present invention, when the document information is transmitted by the transmitting means, the mode setting state is transmitted as mode information.

Accordingly, the transmitting apparatus can notify the receiving apparatus of the mode in which the transmitted document information was transmitted, and appropriate transmission control can be performed according to the mode. Becomes

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is an embodiment in which the present invention is applied to a viewer system and a transmitting device used for the document information transmitting system and the information information transmitting device according to the present invention.

(1) Configuration of Viewer System As shown in FIG. 1, a viewer system 100 as a document information transmission system according to the present embodiment transmits document information composed of characters or images using a direct diffusion method. The transmitting apparatus 200 includes a transmitting apparatus 200 and a viewer 300 as a receiving apparatus that receives the document information transmitted from the transmitting apparatus 200 and displays and reproduces the received document information.

Here, the configuration of the transmitting apparatus 200 will be described with reference to FIG.

As shown in FIG. 2, the transmitting apparatus 200 includes a personal computer 210 for generating document information, and a transmission data D (FIG. 9) which is connected to the personal computer 210 and converts the document information generated by the personal computer 210 into transmission data D (FIG. 9). ) And the transmission data D
And a transmission unit 220 that performs modulation, spreading, amplification, and the like, and generates a spread signal, and a transmission antenna 230 provided in the transmission unit 220 and transmitting the spread signal.

The transmission unit 220 further includes a transmission control section 240 and a transmission section 250. Transmission unit 250
Is connected to a transmission antenna 230. The transmission control unit 240 converts the document information generated by the personal computer 210 into transmission data D having a data format as shown in FIG. 9 and outputs the transmission data D to the transmission unit 250. The configuration of the transmission data D will be described later.

Here, the transmission control section 240 is provided with a storage circuit (not shown) storing various programs for controlling the transmission device 200. A transmission program for performing document information transmission processing is stored in the storage circuit, and the transmission control unit 240 performs document information transmission processing described later based on the transmission program. In addition, the transmission control unit 240
It also has a function of performing error detection and correction processing.

Next, the operation of the transmission control unit 240 and the transmission unit 250 of the transmission device 200 will be described with reference to FIG.

The transmission control unit 240, as shown in FIG.
A spreading code generator 258 and a channel selector 256 are provided. The spreading code generator 258 generates a spreading code such as a generally known M-sequence code or Barker code. For example, the spreading code generator 258 includes a shift register with taps and an adder, or stores a spreading code in advance. It consists of a storage device. The channel selector 256 includes the transmitting unit 2
The frequency data is given to 50 PLL circuits 254.

The transmitting section 250 includes a modulator 251, a spreader 255, an up-converter 252, a power amplifier 253, and a PLL circuit 254, as shown in FIG.
With such a configuration, the modulator 251 includes the transmission control unit 24
The transmission data D output from 0 is received, and the transmission data D is modulated to generate a modulated signal. Then, the generated modulation signal is multiplied by a spread code generated from a spread code generator 258 by a spreader 255 to spread the spectrum. Then, the up-converter 252 receives the oscillation output of the PLL circuit 254 at the oscillation frequency corresponding to the frequency data given from the channel selector 256, shifts the frequency of the spread signal higher by the oscillation frequency, and A channel is set for the frequency. Further, power amplifier 253 amplifies the spread signal output from up-converter 252 and outputs the amplified spread signal to transmission antenna 230.

Here, transmitting apparatus 200 according to the present embodiment
, Two types of modes, a high-speed mode in which the bit rate of the transmission data D is increased and a low-speed mode in which the bit rate is reduced, are provided for switching control. In order to keep the transmission bandwidth constant, the length of the spreading code (spreading code length) generated from the spreading code generator 258 is shortened in the high-speed mode, Mode is longer. Hereinafter, the relationship between the bit rate of the transmission data D and the spreading code length will be described with reference to FIGS.
The description will be made mainly from the aspect of the power spectrum characteristics of the transmission signal.

FIG. 4A is a diagram showing power spectra before and after spreading in the high-speed mode. It can be seen that the power spectrum before spreading (left side) is distributed around the carrier frequency with a bandwidth B1 determined by the bit rate of the high-speed mode. On the other hand, the power spectrum after spreading (right side) has a predetermined occupied bandwidth Bs
You can see how it spreads out in the range. Here, this Bs
The ratio between B1 and B1 is called the spreading factor (processing gain), and it can be considered that the original power spectrum is spread over the bandwidth multiplied by the spreading factor by spreading the signal. That is, when the bandwidth B1 before spreading is multiplied by the spreading factor, the bandwidth Bs after spreading is obtained.

Here, Bs has a predetermined size as an occupied bandwidth. Therefore, in the high-speed mode, the bit rate is large, so that B1 is widened. As a result, the spreading factor is limited to Bs, and the spreading factor cannot be increased so much. The power spectrum of the spread bandwidth Bs is displayed on the viewer 300
, And is despread to return to the original power spectrum of the bandwidth B1.

FIG. 4B is a diagram showing power spectra before and after spreading in the case of the low-speed mode. As in FIG. 4A, the power spectrum before spreading (left side) is such that the power spectrum is distributed around the carrier frequency in a bandwidth B2 determined by the bit rate of the low-speed mode, and the spread power spectrum ( (Right side) extends in the range of the predetermined occupied bandwidth Bs.

In the low-speed mode, since the bit rate is small, B2 is narrowed. As a result, the ratio between Bs and B2 can be increased to increase the spreading factor. Again,
The power spectrum of the spread bandwidth Bs is
After being received at 00, it is despread to return to the original power spectrum of bandwidth B2.

The spreading factor matches the spreading code length of a predetermined spreading code to be multiplied by the spreader 255 with respect to the bit section of the transmission data D. In this embodiment, the spreading factor in the high-speed mode, that is, the spreading code length, is set to 11, and the spreading factor in the low-speed mode, that is, the spreading code length, is set to 110. FIG. 5 shows a spread code c0 with a spread code length of 11 used in the high-speed mode and a spread code c1 with a spread code length of 110 used in the low-speed mode. As described above, the spreading codes c0 and c1 are such that 1 or -1 is arranged in a predetermined pattern by the spreading code length, and the spreader 255 assigns 1 to the bit section of the modulation signal in the order of this pattern. Or -1 is multiplied.

The two modes described above are appropriately switched and set by the transmission control unit 240. As described above, the bit rate of the transmission data D is large in the high-speed mode and small in the low-speed mode. When transmitting information to the viewer 300 at high speed, it is advantageous to use the high-speed mode. However, in the direct spreading method, the degree to which unnecessary waves such as noise and interference waves other than the desired wave are removed through the process of spreading and despreading, that is, the resistance to unnecessary waves, increases as the processing gain increases. Since the processing gain matches the spreading factor, when noise or the like comes from the outside during transmission, the effect is large in the high-speed mode with a small spreading factor and small in the low-speed mode with a large spreading factor. Therefore, the error rate due to wireless transmission can be made relatively smaller when transmitting using the low-speed mode than when transmitting using the high-speed mode.

FIG. 6 is a diagram showing the relationship between the S / N ratio and the error rate for different spreading factors. As shown in FIG. 6, it can be seen that the error rate of wireless transmission increases uniformly as the S / N ratio deteriorates. At this time, what kind of S / N ratio is higher when the spreading factor is higher than when the spreading factor is lower?
As for the ratio, it can be seen that the error rate is small. In the case of the present embodiment, the spreading factor of the low-speed mode and the high-speed mode is about 10 times, and switching the mode generally corresponds to changing the S / N ratio by about 10 dB. As described above, in the low-speed mode having a large spreading factor, although the transmission bit rate is small, the error rate is also small, so that the reliability of wireless transmission can be improved.

Next, the configuration of the viewer 300 will be described with reference to FIG.

As shown in FIG. 7, the viewer 300 receives a spread signal transmitted from the transmitting apparatus 200 as a receiving antenna 310, performs despreading and demodulation on the received spread signal, and performs the original transmission. A receiving unit 320 for restoring the data D, a receiving control unit 330 for performing error correction and the like on the transmission data D and extracting document information from the transmission data D, a display control unit 340 for controlling display switching and the like, A storage circuit 341 provided in the control unit 340 to store the document information extracted by the reception control unit 330, a display unit 350 including a liquid crystal panel or the like for displaying the document information, and the display control unit 340 An input unit 360 for inputting a display switching command, page designation, and the like.

Here, the operation of the receiving section 320 and the receiving control section 330 will be described in more detail with reference to FIG. As shown in FIG. 8, the receiving section 320 includes a low noise amplifier 321, a down converter 322, a despreader 323, a demodulator 324, and a PLL circuit 325.

In the above configuration, the low noise amplifier 321
Amplifies the spread signal received by the receiving antenna 310. Down converter 322 and PLL circuit 325
Is a channel selector 33 provided in the reception control unit 330.
A reception channel is determined using the frequency data given from 1 and the frequency of the spread signal amplified by the low noise amplifier 321 is converted to generate an intermediate frequency signal.

The intermediate frequency signal is supplied to the despreader 3
Despread at 23. More specifically, the reception control unit 33
The spreading code generator 332 outputs the same spreading code as c0 or c1 generated from the spreading code generator 258 of the transmission control unit 240 suitable for the mode at the time of transmission, and applies the same to the despreader 323. Is done. By demodulating the output of the despreader 323 by the demodulator 324, the transmission data D can be restored. As the despreader 323, a sliding correlator, a SAW convolver, a matched filter, or the like is used.

By the way, when despreading is performed using a spreading code different from the spreading code used in the transmitting apparatus 200, the transmission data D cannot be obtained. Therefore, it is necessary for the viewer 300 to recognize whether the transmission was performed in the low-speed mode or the high-speed mode by some method. Therefore, for example, the header S1 of the transmission data D
It is determined whether or not (FIG. 9) has been restored, the mode is recognized from the result, and the same spreading code as the spreading code used by transmitting apparatus 200 can be used.

Further, the reception control unit 330
After error correction or the like is performed on the transmission data D output from, the document information is extracted from the transmission data D and output to the display control unit 340. Here, the reception control unit 330 is provided with a storage circuit (not shown) in which various programs for controlling the viewer 300 are stored. As one of them, there is a reception program for performing document information reception processing, and when the reception control unit 330 outputs the document information to the display control unit 340, the document information reception processing is performed based on this reception program. The document information receiving process will be described later.

The display controller 340, as shown in FIG.
It has a storage circuit 341 for storing the document information extracted by the reception control unit 330. The storage circuit 341 is configured by a rewritable storage element, and
0, so-called VRAM (Vi
deo RAM). That is, the document information written in the storage circuit 341 is displayed on the display unit 350 as it is. The storage circuit 341 is a relatively small-capacity storage circuit having a minimum storage capacity for storing document information that can be displayed at one time (simultaneously) in the display area 351 of the display unit 350. is there. Thus, the storage circuit 3
The storage capacity of the storage circuit 341 can be reduced since the storage capacity of the storage circuit 341 is sufficient as long as it is the minimum necessary to store the document information for one screen of the display unit 350.

As shown in FIG. 1, the display section 350 has a display area 351 large enough to display the document information at a normal scale on one page at a time (simultaneously). For example, the display section 350 has substantially the same area as A4 size paper.

The input section 360 has a plurality of switches provided on the viewer body 301 as shown in FIG. When the receiver operates these switches, a signal corresponding to the switches is input to the display control unit 340. Then, the display control unit 340 controls display switching of the display unit 350 and the like.

(2) Configuration of Document Information and Transmission Data Next, the document information and transmission data D generated by the transmitting device 200 are shown in FIGS. 9, 14, 15, and 17.
It will be described according to.

FIG. 14 shows, for example, document information N1, N2, N3 consisting of three pages. As described above, the document information N1, N2, and N3 are information in which characters or images are recorded in page units, and are generated by, for example, a word processor program or a graphic creation program of the personal computer 210. Here, "page"
In the case where the document information is divided in an appropriate amount unit, this means one division. For example, when the document information is printed on A4 size paper, it means one division divided by the area of the paper. One section divided by an amount that can be displayed at one time on the display unit 350 of the viewer can be regarded as a page.

The document information is data generated by the personal computer 210, and has a different data format depending on whether the information included in the document information is a character or an image, as described below. That is, in the case of document information consisting only of characters, the document information is ASCII code (US standard code for information exchange), JIS code or EB code.
It is composed of text data (character data) including a CDIC code (extended binary coded decimal code) and the like. On the other hand, in the case of document information including an image, the document information is constituted by bitmap data.

When the document information is transmitted from the transmitting device 200 to the viewer 300, the document information is transmitted as shown in FIG.
As shown in FIG. 17, each page is divided into a plurality of blocks a and transmitted in block units. Here, when the document information is text data, the document information is divided so that the number of characters constituting one block a is smaller than the number of characters for one line of each page of the document information as shown in FIG. You. When the character information is graphic data (bitmap data), as shown in FIG. 17, the number of bits of the bitmap data constituting one block corresponds to the number of bits constituting one line (line element) of the page. It is divided so as to be an integral multiple of the number of bits of the map data. Note that the document information may be divided so that the number of bits of bitmap data forming one block is equal to or less than the number of bits of bitmap data forming one line (line element) of the page.

Further, when the document information is transmitted from the transmitting apparatus 200 to the viewer 300, each block a constituting the document information is converted into transmission data D having a plurality of frames F as shown in FIG. You. Each frame F in the transmission data D includes a header S1 and a document data area S2.

The header S1 includes the ID of the viewer 300 receiving the transmission data D, page information indicating the page number of the page to which the frame F belongs, block information indicating the block to which the frame F belongs, and various types of information. Control information is recorded. Here, the control information is information indicating whether or not the frame F is transmitted in the page designation transmission mode, information indicating whether or not the contents of characters or images recorded on the page to which the frame F belongs have been changed, Information indicating the display format of the page to which the frame F belongs, information indicating whether the data recorded in the document data area S2 of the frame F is text data or graphic data, information indicating the page size of the page to which the frame F belongs, etc. It is.

In the document data area S2, text data or graphic data indicating characters or images are recorded. Note that the reception control unit 330 of the viewer 300
However, when extracting the document information from the despread transmission data D and recording the document information in the storage circuit 341 of the display control unit 340, the data recorded in the document information data area S2 of the transmission data D is extracted and stored in the storage circuit 341. To memorize.

(3) Document Information Transmission Process Next, the document information transmission process executed by the transmission control unit 240 of the transmission device 200 will be described with reference to the flowchart of FIG.

When the sender operates personal computer 210 to transmit the document information generated by personal computer 210 of transmitting apparatus 200, the document information is output from personal computer 210 to transmission control section 240. At this time, the transmission control unit 240
Starts the transmission program stored in the storage circuit of the transmission control unit 240, and the document information transmission process described below starts.

As shown in FIG. 10, first, in step S1
Then, the power is supplied to the transmitting unit 250 whose power has been turned off until now, and the transmitting unit 250 is turned on.

In step S2, the control information output from the personal computer 210 is read, and it is determined whether the mode is the "page transmission designation mode" or the "all page transmission mode".

Here, the “page designation transmission mode” is
In this mode, the transmitting apparatus 200 specifies a page number of document information to be transmitted and transmits the specified one page of document information. Therefore, in the “page designation transmission mode”, even when the document information covers a plurality of pages, the transmission device 2
From 00, only the specified one page of document information is transmitted. On the other hand, the “all page transmission mode” is a mode in which all pages of document information of a plurality of pages are transmitted without specifying a page.

The personal computer 210 outputs control information for controlling the document information in addition to the document information. The control information includes an ID of the viewer 300 that transmits the document information, information about a page of the document information, information indicating whether the document information is transmitted in the page designation transmission mode, information indicating a display format of each page of the document information, Information indicating whether the document information is text data or graphic data, information indicating the page size of the document information, and the like.

That is, in step S2, based on the control information output from the personal computer 210, it is determined whether or not the document information to be transmitted is to be transmitted in the page designation transmission mode. As a result, when the document information is transmitted in the page designation transmission mode, the process proceeds to step S3.

In step S3, if the document information covers a plurality of pages, a page number to be transmitted is set from the document information of the plurality of pages. That is,
When transmitting document information in the page specification transmission mode,
The sender operates the personal computer 210 to set the page number of the document information to be transmitted. The page number is output from the personal computer 210 to the transmission control unit 240 as a control signal. In step S3, a page number to be transmitted is recognized based on the control information.

In step S4, two modes that can be switched as the bit rate of the transmission data D are set to the high-speed mode. In other words, at the time of the first transmission after the transmission is started, the setting is such that the transmission data has a higher speed than the reduction of the data transmission error rate. In this high-speed mode, the length of the spreading code generated from the spreading code generator 258 is reduced, and the data rate of the information signal sent to the modulator 251 is increased.

In step S5, one page of document information corresponding to the page number set in step S3 is divided into a plurality of blocks a (see FIGS. 15 and 17), and the transmission data D ( (See FIG. 9). At this time, each frame F constituting the transmission data D
Is generated based on control information output from the personal computer 210 and the like. The transmission data D converted in step S4 is modulated and spread by the transmission unit 250, and transmitted from the transmission antenna 230 to the viewer 300 in block units.

Here, the viewer 300 cannot always immediately recognize whether the transmission is performed in the high-speed mode or the low-speed mode. Therefore, before transmitting the document information, in order to easily recognize which of the two modes the transmission is being performed prior to the reception of the document information, only the header S1 or the document is transmitted. By adding dummy data to the data area S2,
The transmission operation may be repeated several times. As a result, when the mode has not been recognized yet, such as immediately after transmission,
A situation in which the received data is partially lost can be prevented, and the reliability is further improved.

In step S6, it is determined whether or not transmission of one page of document information (transmission data D) corresponding to the page number set in step S3 has been completed.
If the transmission of the document information for one page has not been completed, the process returns to step S5, and returns to step S5 and step S5.
6 is repeated until the transmission of the document information for one page is completed.

In step S7, it is determined whether or not to end the document information transmission processing. For example, viewer system 1
When the transmission of the document information is stopped, or when all the viewers 300 that receive the document information transmitted from the transmission device 200 are in the hold state, the document transmission process by the transmission device 200 ends. In this case, the sender operates personal computer 210 and inputs a command to end document information transmission processing by transmitting apparatus 200. Accordingly, this command is transmitted from personal computer 210 to transmission control unit 240 as control information. Therefore, in step S7, it is determined whether or not to end the document information transmission process by the transmission device 200 based on the control information.

Then, as a result of the determination in step S7, when the document information transmitting process is to be ended, the process proceeds to step S14, and the power of the transmitting unit 250 is turned off. On the other hand, if the result of determination in step S7 is that the document information transmission process is not to be ended, the process moves to step S8.

In step S8, it is determined whether or not the page of the document information to be transmitted has been changed. That is, when the sender operates the personal computer 210 and inputs a command to change the page of the document information to be transmitted, the command is output from the personal computer 210 to the transmission control unit 240 as a control signal. You. Therefore, in step S8, it is determined whether the page of the document information to be transmitted has been changed based on the control signal.

When the page of the document information to be transmitted is changed as a result of the determination in step S8, the process proceeds to step S3, and a new page number is set in steps S3 to S6, and the new page number is set. The document information for one page corresponding to the number is transmitted. On the other hand, step S
If the result of determination in step 8 is that the page of the document information to be transmitted has not been changed, the flow shifts to step S9 to set the low-speed mode. In the low speed mode, the spreading code generator 258
, The length of the spreading code generated from the data becomes longer, and the data rate of the information signal sent to the modulator 251 becomes slower. On the other hand, during data transmission, as described above, it is advantageous to reduce the error rate.

Thereafter, the flow shifts to step S5, and the document of the same page is repeatedly transmitted by the processing of step S5 and step S6. That is, 1 in the viewer 300
Even if an error occurs during the second reception in the high-speed mode, by switching the second and subsequent transmissions to the low-speed mode, the document information can be re-received in the low-speed mode. It is possible to realize transmission of various document information. Immediately after the transmission mode is switched to the low-speed mode, the viewer 300 cannot always immediately recognize the mode. Therefore, upon transmission, the header S1 is repeatedly transmitted several times, or dummy data is added to the document data area S2. May be transmitted. Thus, after the mode is switched, the document information itself is transmitted after the viewer 300 recognizes the mode, so that the reception is performed without loss of the document information, and the smooth data transmission is performed.

In the present embodiment, a case has been described in which transmission is performed only in the first mode in the high-speed mode and transmission is repeated in the low-speed mode after the second time. After the transmission, it is possible to repeat the transmission once again in the high-speed mode and then perform the transmission in the low-speed mode a predetermined number of times. Further, it is also possible to perform transmission in the high-speed mode as needed by operating the personal computer 210. Thus, even when the viewer 300 is turned on during a meeting or when the viewer 300 is reset during a meeting, a document can be displayed at high speed.

On the other hand, as a result of the determination in step S2,
If it is not the page designation transmission mode, that is, if it is the all page transmission mode, the process proceeds to step S10.

In step S10, two modes that can be switched as the bit rate of the transmission data D are set to the high-speed mode. As in step 4, since the transmission is started and the first transmission is performed, the setting is such that the transmission data has a higher speed than the reduction in the data transmission error rate. Therefore, the length of the spreading code generated from spreading code generator 258 is reduced, and the data rate of the information signal sent to modulator 251 is increased.

At step S11, all pages of the document information over a plurality of pages are transmitted. That is, the document information covering a plurality of pages is divided into a plurality of blocks a, converted into transmission data D, and output to the transmission unit 250. As a result, the transmission data D is modulated and spread by the transmission unit 250, and is simultaneously transmitted from the transmission antenna 230 to the viewer 300 in block units. At this time, the transmission order of each block is controlled by a transmission order control process. The transmission order control processing will be described later.

In step S12, it is determined whether all pages of document information for a plurality of pages have been transmitted. as a result,
If the document information has not been transmitted to all pages, the process returns to step S11, and steps S11 and S12 are repeated until the document information is transmitted to all pages. On the other hand, when the document information has been transmitted to all pages, the process proceeds to step S13, and it is determined whether or not the document information processing is to be ended, as in step S7 described above.

Then, as a result of the determination in step S13, when the document information transmission process is to be terminated, the power of the transmission section 250 is turned off in step S14, and the document information transmission process is terminated. On the other hand, if the document information transmission process is not to be ended, the process proceeds to step S15.

In step S15, it is determined whether or not the contents of the document to be transmitted have been changed by operating the personal computer 210 or the like. If there is a change in the document content, the transmission is performed for the first time, so the flow shifts to step S16 to set the high-speed mode. Then, step S1
1 and the document information including the changed content is transmitted at a high speed. On the other hand, if there is no change in the contents of the document, step S
Move to 17.

In step S17, it is determined whether transmission has been completed a predetermined number of times continuously in the low-speed mode. As a result, if the predetermined number of transmissions have not been completed, the process proceeds to step S18, where the mode is switched to the low-speed mode, and then returns to step S11 to repeatedly transmit document information over a plurality of pages. On the other hand, when the transmission has been completed the predetermined number of times, the process proceeds to step S19, where the mode is switched again to the high-speed mode. Then, the process returns to step S11 to transmit the document information over a plurality of pages. Thus, even when the viewer 300 is turned on during the meeting or when the viewer 300 is reset during the meeting, the document can be displayed at high speed. Note that, besides the method of determining the number of transmissions in the low-speed mode in advance as in the present embodiment, the personal computer 21
The operation may be switched from the low-speed mode to the high-speed mode as appropriate by the operation of 0.

As described above, according to the document information transmission process, in the page designation transmission mode, the transmission device 200
Unless the sender inputs a command to the personal computer 210 to end the document information transmission process,
The document information for the page is continuously transmitted to the viewer 300 repeatedly. In particular, when the page number of the document information to be transmitted is not changed, the transmission device 200 continues to repeatedly transmit the document information of the same page to the viewer 300.

On the other hand, in the case of the all-page transmission mode, transmitting apparatus 200 transmits all the document information of a plurality of pages unless the sender inputs a command to end the document information transmission processing to personal computer 210. The page is repeatedly transmitted to the viewer 300.

(4) Document Information Reception Processing Next, document information reception processing executed by the reception control section 330 of the viewer 300 will be described with reference to the flowcharts of FIGS.

When the receiver starts the viewer 300 to obtain the document information transmitted from the transmitting device 200, the power of the reception control unit 330 is turned on, and the reception program stored in the storage circuit of the reception control unit 330 is started. Then, the document information receiving process described below starts.

As shown in FIG. 11, first, in step S2
1, the power is supplied to the receiving unit 320, and the receiving unit 3
20 is turned on. Thereby, receiving section 320 receives the spread signal transmitted from transmitting apparatus 200. In addition,
A reception frequency is set in advance by the channel selector 331 so that the spread signal transmitted from the transmission device 200 can be received.

In step S22, two modes that can be switched as the bit rate for the received data are set to the high-speed mode. In the high-speed mode, a spreading code having a short code length is generated from the spreading code generator 332 of the reception control unit 330. Then, despreading and demodulation are performed using this spreading code.

In step S23, it is determined whether or not the header S1 of the transmission data D can be restored. If the header S1 can be detected, the transmission device 200 is also set to the high-speed mode and uses the same spreading code. Therefore, despreading is performed using the spreading code, and the receiving operation is continued.

On the other hand, if the header S1 cannot be detected, it is assumed that the transmission device 200 is set to the low-speed mode because different spreading codes are used in the transmission device 200 and the viewer 300. for that reason,
In step S24, a setting is made to switch to the low-speed mode. In this low-speed mode, a spreading code having a long code length is generated from the spreading code generator 332 of the reception signal control unit 330.

Then, in step S25, despreading is performed again.
Demodulation is performed to determine whether the header S1 of the transmission data D can be restored. As a result, when the header S1 cannot be detected, the process returns to step S22, and further attempts to detect the header S1. On the other hand, when the header S1 can be detected, it is confirmed that the signal can be received in the low-speed mode. Therefore, the receiving operation is continued, and the process proceeds to step S26. Note that the demodulated transmission data D is input to the reception control unit 330.

In step S26, the contents of the header S1 of each frame F constituting the transmission data D are checked, and the document information (transmission data D) is transmitted in either the "page designation mode" or the "all page transmission mode". Is determined. As a result, when the document information is transmitted in the “page designation transmission mode”, the process proceeds to step S27 in FIG.

In step S27 in FIG. 12, it is determined whether or not header S1 of transmission data D can be detected. As a result, when the header S1 cannot be detected, step S28
Then, the mode is switched and the header S1 is detected again. That is, if the header S1 cannot be detected in the high-speed mode, the mode is switched to the low-speed mode. If the header S1 cannot be detected in the low-speed mode, the mode is switched to the high-speed mode. On the other hand, if the header S1 can be detected in step 27,
Move to step S29.

In step S29, one block of the document information transmitted from transmitting apparatus 200 is received. More specifically, the receiving unit 320 restores the transmission data D based on the spread signal transmitted from the transmitting device 200, and the reception control unit 330 transmits the document data area of each frame F constituting the transmission data D. The document information recorded in S2 is extracted for one block.

In step S30, it is determined whether or not there is an error in the document information of one block received in step S29. As a result, when there is no error, in step S31, this one block of document information is displayed on the display control unit 3.
40 are written to the storage circuit 341. When the document information is written in the storage circuit 341, the written document information is displayed on the display unit 350.

On the other hand, if the result of determination in step S30 is that there is an error, in step S32, this one block of document information is discarded without writing to the storage circuit 341.
Thus, an unwritten area is formed in the storage circuit 341. In this case, the display unit 350 displays the information shown in FIG.
5 or a blank b is displayed as shown in FIG.

Here, FIGS. 15 and 16 show segmentation information composed of text data for one page, and N1 (left side) when all blocks are normally received and an error occurs during reception. , N1 ′ (right side) when blocks could not be partially received. FIG. 17 shows document information composed of graphic data for one page, N4 (upper side) when all blocks are normally received, and an error occurs during reception, and blocks can be partially received. N4 '(lower side) in the case where there is no such information is shown.

That is, when an error occurs during reception and one block of document information composed of text data cannot be received, as shown in FIG.
Blocks become blank b. Here, as described above,
When transmitting the document information composed of text data by the transmission device 200, the document information is divided so that the number of characters constituting one block a is smaller than the number of characters for one line of each page of the document information. You. Thus, even if a blank b for one block is formed in the document information due to a reception error, the area of the blank b is small, and
Fits within a line. Therefore, even if a reception error occurs, the receiver can understand the contents of the document information by viewing the entire page of the document information.

If there is document information previously written in the storage circuit 341 (hereinafter referred to as "previous information c"), as shown in FIG. 16, the previous information c remains without being rewritten. In this case, the previous information c is displayed on the display unit 350. At this time, in addition to displaying the previous information c, the color and font of the previous information c may be changed, or the previous information c may be underlined to notify the receiver of the occurrence of the error. It may be.

Further, when an error occurs during reception and one block of document information composed of graphic data cannot be received, one block that cannot be received becomes blank b as shown in FIG. Here, as described above, when transmitting text information composed of graphic data by the transmission device 200, the text information is such that the number of bits of bitmap data constituting one block is one line (line element) of the page. Are divided so as to be an integral multiple of the number of bits of the bitmap data constituting As a result, even if a blank b for one block is formed in the document information due to a reception error, the area of the blank b is small, and a small blank line is formed in the document information. Therefore, even if a reception error occurs, the receiver can understand the contents of the document information by viewing the entire page of the document information.

By the way, in step S33 in FIG.
It is determined whether all the document information for the page has been received.
As a result, when all the document information for one page has not been received, the process returns to step S29, and until all document information for one page has been received, steps S29 to S3 are performed.
Step 3 is repeated.

Subsequently, in step S34, step S
By the processing of steps 29 to S33, the document information of one page transmitted from the transmission device 200 is displayed on the display control unit 34.
It is determined whether the data has been completely written to the storage circuit 341 of “0”. That is, if there is no error during the reception of one page of document information by the processing of steps S29 to S33, the received document information is completely written into the storage circuit 341. If there is an error during the reception of, there is a portion that is not written in the storage circuit 341. Therefore, in step S34, it is determined whether or not one page of document information has been completely written into the storage circuit 341, and if there is a portion that is not written in the storage circuit 341, it is determined that an error has occurred during reception. It returns to step S27. Then, step S2
The processes from 7 to S33 are repeatedly executed.

Here, transmitting apparatus 200 repeatedly transmits one page of document information by repeating the above-described processing. Therefore, if there is an error while the viewer 300 receives one page of document information, the document information can be received again. Especially,
When the transmitting apparatus 200 is transmitting document information in the low-speed mode, the error rate becomes very low. Therefore, even if an error has occurred during the previous reception, the error is correctly corrected by re-receiving the document. Can receive,
More complete display can be performed.

On the other hand, when the viewer 300 has completely received the document information of one page repeatedly transmitted from the transmission device 200 and completely written the storage circuit 341 of the display control unit 340, “YES” is determined in step S34. , And the process moves to step S35. At this time, since one page of document information has been completely written in the storage circuit 341, the one page of document information is completely and accurately displayed on the display unit 350. That is, even if an error occurs during the first reception and a blank b is formed as shown on the right side in FIG. 15 and the lower side in FIG. 17, the processes of steps S27 to S33 are repeatedly executed, and the same contents are obtained. By receiving the document information a plurality of times, the error can be eliminated, and the document information for one page can be completely displayed as shown on the left side in FIG. 15 and the upper side in FIG.

In step S35, the low noise amplifier 321, down converter 322, despreader 3
The power of the demodulator 23 and the demodulator 324 is turned off, and a so-called sleep state is set. Thus, power consumption can be reduced. Note that even during the sleep state, the PLL circuit 32
The power of No. 5 is turned on. Thereby, the PLL circuit 3
It is possible to stabilize the oscillation frequency of 25, and to immediately start the receiving operation on a predetermined channel when the sleep state is released.

In step S36, it is determined whether to hold the viewer 300 or to terminate the document information receiving process. Here, “hold” means to turn off the power of the receiving unit 320, the receiving control unit 330, and the like while the received document information is displayed on the display unit 350. To specify the hold, the input unit 360 of the viewer 300 is operated. When the viewer 300 is held, the display on the display unit 350 can be fixed and the power consumption can be minimized.

In step S37, it is determined whether or not a predetermined time has elapsed since the viewer 300 went to sleep in step S35. As a result, when the predetermined time has elapsed, the viewer 300 is woken in step S38. That is, the low noise amplifier 32 of the receiving unit 320
1. Power on the down converter 322, despreader 323 and demodulator 324.

Then, in step S39, the transmitting device 20
It is determined whether the header S1 transmitted from 0 can be detected. As a result, if the header S1 cannot be detected, in step S40, the mode is set by switching from the low-speed mode to the high-speed mode or from the high-speed mode to the low-speed mode. On the other hand, when the header S1 can be detected, the process proceeds to step S42.

When the mode is switched in step S40, similar detection of a header is repeated again, but the number of repetitions is limited to a predetermined number. Thus, in step S41, it is determined whether or not the process has been repeated a predetermined number of times. As a result, if the number has not reached the predetermined number, the process proceeds to step S39 to detect the header S1 again. On the other hand, when the predetermined number of times has elapsed, the process proceeds to step 62, and the viewer 300 is set to the hold state.

In step S42, it is determined whether the page number of the document information transmitted from transmitting apparatus 200 has been changed or the content of the document information transmitted from transmitting apparatus 200 has been changed. As a result, the transmission device 200
When the page number or the content of the document information transmitted from is changed, the process returns to step S27 to receive the changed new one-page document information and display it on the display unit 350. On the other hand, if it has not been changed, step S3
Returning to 5, the viewer 300 goes to sleep again. Note that whether or not the content of the document information transmitted from the transmission device 200 has been changed is recorded in the header S1 of each frame F constituting the transmission data D. Therefore, by examining the content of these headers S1, Can be recognized.

As described above, steps S35 to S
By the process of 42, the viewer 300 wakes up periodically at predetermined time intervals, receives document information only when there is a change in the document information displayed on the display unit 350 of the viewer 300, and at other times Is mainly in a sleep state.

On the other hand, if the result of determination in step S 26 in FIG. 11 is that document information has been transmitted in “all pages transmission mode” from transmitting apparatus 200, the flow shifts to step S 43.

In step S43, a reception page is set by the input section 360 of the viewer 300. That is, the receiver operates a switch provided on the viewer body 301 of the viewer 300 to set a page number of document information to be displayed on the viewer 300.

Next, in step S44, the viewer 3
00 determines whether the header S1 can be detected. As a result, when the header S1 cannot be detected, step S4
At 5, the switching from the high-speed mode to the low-speed mode or from the low-speed mode to the high-speed mode is set, and the process returns to step S44 to try to detect the header S1 again. on the other hand,
If the header S1 can be detected, the process proceeds to step S46.

At step S46, the document information of the page number set at step 43 is received. More specifically, since the transmitting device 200 repeatedly transmits all pages of the document information over a plurality of pages, the reception control unit 330 of the viewer 300 firstly transmits each block of the received transmission data D for one block. By examining the header S1 of the frame F, the page number of the page to which the frame F belongs is recognized. Then, when the recognized page number matches the page number input by the receiver using the input unit 360, one block of the document information recorded in the document data area S2 of the frame F is extracted.

In the step S47, it is determined whether or not there is an error in the document information of one block received in the step S46. As a result, when there is no error, in step S48, the received document information of one block is written into the storage circuit 341 of the display control unit 340. As a result, the received document information of one block is displayed on the display unit 35.
Displayed as 0. On the other hand, if the result of determination is that there is an error in receiving the document information for one block, step S49
Then, this document information is discarded without being written in the storage circuit 341. Thus, an unwritten area is formed in the storage circuit 341. In this case, the display unit 350 displays blank or displays previously written document information (previous information).

At step S50, the receiver sets the viewer 3
It is determined whether the page number of the document information to be displayed on the viewer 300 has been changed by operating the input unit 360 of 00. As a result, when the page number or the content of the document information transmitted from the transmitting device 200 has been changed, the process returns to step S43 to perform the reception again, and when the document information has not been changed, the process proceeds to step S51.

In step S51, it is determined whether the reception of the document information of one page set in step S43 among the document information of a plurality of pages transmitted from the transmission device 200 has been completed. As a result, when the reception of the document information for one page is not completed, the process returns to step S46, and the processing of steps S46 to S51 is repeated until the reception of the document information for one page is completed. The document information is written into the storage circuit 341.

In step S52, the above-described step S52 is executed.
34, the storage circuit 341 of the display control unit 340.
It is determined whether the document information for one page has been completely written. As a result, when the document information for one page has not been completely written in the storage circuit 341,
Since it means that there is an error during the reception of the document information for one page, the process shifts to step S43 to receive the document information for one page again.

Here, since transmitting apparatus 200 repeatedly transmits document information of a plurality of pages for all pages, if there is an error while receiving one page of document information designated by viewer 300, Thus, the designated one page of document information can be received again. In particular, even when an error occurs when the transmitting apparatus 200 first performs transmission using the high-speed mode, the error rate can be reduced by performing transmission using the second and subsequent low-speed modes. Therefore, even if you receive a document at high speed and display it first,
By re-receiving the data in the low-speed mode, the error can be almost certainly eliminated, and more complete document information can be displayed.

On the other hand, one page of the document information repeatedly transmitted from the transmitting device 200 is completely received by the viewer 300, and one page of this document is completely written in the storage circuit 341 of the display control unit 340. At this time, “YES” is determined in the step S52, and the process shifts to the step S53. At this time, since one page of document information has been completely written in the storage circuit 341, the one page of document information is completely displayed on the display unit 350.

In step S53, the aforementioned step S
35, the low noise amplifier 321, the down converter 322, the despreader 323, and the demodulator 32 of the receiving unit 320.
4 is turned off, and the viewer 300 is put into a so-called sleep state. In step S54, the viewer 3
It is determined whether to hold 00 or to end the document information receiving process.

In step S55, during the sleep state,
It is determined whether the receiver operates the input unit 360 of the viewer 300 and changes the page number of the document information to be displayed on the viewer 300. As a result, when there is a page change, the sleep is released and the process proceeds to step S43.
The document information of the new page is received and displayed on the display unit 350.

In step S56, it is determined whether or not a predetermined time has elapsed since the viewer 300 was put to sleep in step S53. As a result, when the predetermined time has elapsed, the viewer 300 is woken in step S57.

In the step S58, it is determined whether or not the header S1 can be detected. As a result, when the header S1 cannot be detected, in step S59, switching from the high-speed mode to the low-speed mode or switching from the low-speed mode to the high-speed mode is performed, and the process proceeds to step S60. on the other hand,
If the result of the determination is that the header S1 can be detected, the flow proceeds to step S61.

In step S60, it is determined whether or not the transmission has been completed a predetermined number of times. As a result, if the transmission has not been completed the predetermined number of times, the process shifts to step S58 to try to detect the header S1 again. On the other hand, when the transmission has been completed the predetermined number of times, the process proceeds to step S62.

In step S61, it is determined whether the page number of the document information transmitted from the transmitting device 200 has been changed, whether the content of the document information transmitted from the transmitting device 200 has been changed, or Input unit 360
Is operated to change the page number of the document information to be displayed on the viewer 300. Whether or not the content of the document information transmitted from the transmitting device 200 has been changed can be recognized by checking the content of the header S1 of each frame F constituting the transmission data D. as a result,
When the page number or content of the document information is changed,
Returning to step S 43, the changed document information of one page is received and displayed on the display unit 350. On the other hand, if the result of determination in step S61 is that the page number or content of the document information has not been changed, processing returns to step S53. As a result, the viewer 300 returns to the sleep state.

As described above, steps S53 to S53
By the process of 61, the viewer 300 wakes up periodically at predetermined time intervals, receives document information only when there is a change in the document information displayed on the display unit 350 of the viewer 300, and at other times Goes to sleep.

On the other hand, step S36 or step S54
As a result of the determination, when the viewer 300 is to be held or the document information receiving process is to be ended, the process proceeds to step S62 in FIG. 13 and the power of the receiving unit 320 is turned off. Then, when ending the document information receiving process, "YES" is determined in the step S63, and the document information receiving process ends. On the other hand, when releasing the hold of the viewer 300, “YES” is determined in the step S64, and the process shifts to the step S21 in FIG. Thus, the viewer 300 receives the document information transmitted from the transmitting device 200 again.

(5) Transmission Order Control Processing Next, referring to FIG. 18 and FIG. 19, when transmitting apparatus 200 transmits document information in units of blocks, transmission order control for controlling the transmission order of each block is performed. The processing will be described.

As described above, in the document information transmission process executed by the transmission control unit 240 of the transmission device 200,
The document information is divided into blocks, and the document information is modulated, spread, and transmitted for each block (step S5 or step S11 in FIG. 10). At this time, the transmission order of each block is controlled by a transmission order control process executed by the transmission control unit 240. According to the transmission order control process, the transmission order of each block has the following three patterns.

The first pattern is as shown in FIG.
Each block of the document information is transmitted in that order from the beginning to the end of the document information. Therefore, in the first pattern, for example, the transmitting section 250 first transmits the document information N1 of the first page continuously for one page, and then continuously transmits the document information N2 of the second page for one page. The document information N3 for the third page is transmitted for one page continuously.

The second pattern is as shown in FIG.
The transmission order of each block is controlled such that each time one block is transmitted, a block belonging to a page different from the page to which the previously transmitted block belongs is transmitted. Therefore, in the second pattern, for example, first, the first block of the first page of the document information N1 of the first page is transmitted, and then the first block of the second page of the document information N2 is transmitted. Subsequently, the first of the document information N3 of the third page
The block is sent. As described above, the page is changed every time one block is transmitted, so that the document information of each page is transmitted substantially the same. Therefore, if the document information of a plurality of pages is transmitted in the second pattern, the viewer 300 can quickly set the document information of the set page regardless of which page is to be received among the plurality of pages. Can be received.

The third pattern is that the document information is transmitted from the transmitting device 200 to the viewer 300 until the predetermined time elapses from the start of the transmission of the document information, and then the first pattern is transmitted. Is transmitted in the second pattern.

As described above, according to the viewer system 100 of the present embodiment, the transmitting apparatus 200 transmits document information in which characters or images are recorded in page units, and the viewer 300 transmits the document information transmitted from the transmitting apparatus 200. Since it is configured to receive one page, the sender can easily transmit the document information, and the receiver can easily confirm the transmitted document in page units. Further, since a plurality of pages are transmitted at the same time, the recipient can quickly display a target page.

Therefore, for example, when the viewer system 100 is used for a conference or the like, the paper on which the content of the conference is printed can be eliminated. This saves meeting attendees from having to print meeting materials and sort out each participant,
Meeting efficiency can be improved.

A display unit 3 capable of displaying one page of the document information of the normal scale at a time on the viewer 300.
Since the configuration is provided with 50, the document information can be displayed in a legible manner on the same scale and layout as when the document information is printed on paper. Therefore, the recipient can view the document information with the same feeling as viewing the paper on which the document information is printed, and can understand the contents of the document information accurately and quickly.

The preferred embodiments of the present invention have been described above. However, when the present invention is applied, various embodiments other than the above embodiments are conceivable. Hereinafter, useful modifications will be described.

In the above-described embodiment, the case where transmission is performed in the high-speed mode immediately after the start of transmission and then switching to the low-speed mode has been described. It is not limited. For example, the switching may be performed alternately each time the transmission of the document information is repeated. After transmitting the high-speed mode a plurality of times, the low-speed mode may be transmitted once. In this way, it is possible to quickly display in the high-speed mode, and to correct the last error in the low-speed mode, thereby further reducing the waiting time for display.

In the above embodiment, the case where the bit rate of the transmission data is switched between the high-speed mode and the low-speed mode has been described. However, the number of modes is not limited to two. And a configuration in which the bit rate is set finely.

In the above embodiment, the viewer 300
The side has described the case where the mode is recognized based on whether or not reception can be performed by appropriately switching between the high-speed mode and the low-speed mode. However, the transmitting apparatus 200 adds predetermined mode information to the header S1, and the viewer 300 The mode may be recognized by reading. By doing so, the information to be transmitted from the transmitting device 200 increases,
In the viewer 300, the mode can be quickly switched, and the document information can be displayed more quickly. Furthermore, the viewer 300 may be configured not to recognize such a mode and to receive document information transmitted in either the high-speed mode or the low-speed mode in a fixed manner.

In the above embodiment, the viewer 300
Is configured to display document information for one page at a time, but the present invention is not limited to this, and displays document information for a plurality of pages of about 2 to 4 pages at a time. It may be configured. In this case, the transmission device 200 repeatedly transmits document information of about 2 to 4 pages in the page designation transmission mode. When the document information is transmitted in the all-page transmission mode, the viewer 300 specifies about two to four page numbers.

In the above embodiment, the viewer 300
Has been described in which the display unit 350 has the same area as that of the A4 size paper, but the present invention is not limited to this, and the display unit 350 may be downsized to B5 or A6 size. The size may be increased to about the size. Further, the viewer may be a wall-mounted type.

[0153]

As described above, according to the first aspect of the present invention, when transmitting document information from a transmitting device to a receiving device, a plurality of transmission speeds can be set by switching modes. By appropriately setting the mode in accordance with the situation, it is possible to select an appropriate transmission method, for example, by setting the receiving device to give priority to high-speed display or reliable data transmission. This makes it possible to transmit document information at high speed and with high reliability in a conference or the like.

According to the second aspect of the invention, the transmission of the document information from the transmitting device to the receiving device is performed by the direct spreading method, and the transmission mode can be switched between the low speed mode and the high speed mode. When transmitting document information, an appropriate transmission method can be selected, such as setting a high-speed mode when priority is given to high-speed display, and setting a low-speed mode when priority is given to reliability of data transmission. This makes it possible to transmit document information at high speed in a conference or the like, which is hardly affected by a radio error or the like.

According to the third aspect of the present invention, the mode for setting the transmission speed of the document information is switched in accordance with a preset timing. The transmission can be repeated in various modes, and appropriate transmission according to the contents of the document information can be performed. According to the fourth aspect of the present invention, at the time of receiving document information, the mode of the mode is determined in the receiving apparatus, and the receiving operation is performed according to the result. The reception device can recognize whether the data has been transmitted, and appropriate reception control can be performed according to the mode.

According to the fifth aspect of the present invention, when transmitting the document information, the mode information indicating the mode setting state is transmitted together, and the receiving apparatus receives the mode information together with the document information. Since the mode type is determined, the mode in which the document information was transmitted can be notified from the transmitting device to the receiving device, and appropriate transmission control can be performed according to the mode. It becomes possible.

According to the sixth aspect of the present invention, when transmitting document information from a transmitting apparatus to a receiving apparatus, a plurality of transmission speeds can be set by switching modes, so that the mode is appropriately set according to the situation. By doing so, it is possible to select an appropriate transmission method, for example, by setting the receiving device to give priority to high-speed display or certainty of data transmission. As a result, it is possible to provide a transmission device that performs high-speed and highly reliable transmission of document information in a conference or the like.

According to the seventh aspect of the invention, the transmission of the document information from the transmitting apparatus is performed by the direct spreading method, and the transmission mode can be switched between the low-speed mode and the high-speed mode. At the time of transmission, an appropriate transmission method can be selected, such as setting a high-speed mode when priority is given to high-speed display, and setting a low-speed mode when priority is given to reliability of data transmission. Thus, it is possible to provide a transmission device that transmits document information at a high speed and is not easily affected by a wireless error or the like in a conference or the like.

According to the eighth aspect of the invention, the mode information indicating the mode setting state is transmitted together with the transmission of the document information. Therefore, in which mode the document information is transmitted. Can be reported from the transmitting device to the receiving device, and appropriate transmission control can be performed according to the mode.

[Brief description of the drawings]

FIG. 1 is an overall view showing a viewer system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a transmission device according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a transmission control unit, a transmission unit, and a transmission antenna of the transmission device according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a relationship between a change in a power spectrum due to spreading and a mode in the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing spreading codes used in the transmitting device according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a relationship between an S / N ratio and an error rate when transmission is performed with different spreading factors.

FIG. 7 is a block diagram illustrating a viewer according to an embodiment of the present invention.

FIG. 8 is a block diagram illustrating a receiving antenna, a receiving unit, and a receiving control unit of the viewer according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a configuration of transmission data according to the embodiment of the present invention.

FIG. 10 is a flowchart illustrating a document information transmission process according to the embodiment of the present invention.

FIG. 11 is a flowchart showing a document information receiving process according to the embodiment of the present invention.

FIG. 12 is a flowchart showing a document information receiving process following FIG. 11;

FIG. 13 is a flowchart showing a document information receiving process following FIG.

FIG. 14 is an explanatory diagram showing document information over three pages in the embodiment of the present invention.

FIG. 15 is a diagram illustrating a state in which one page of document information composed of text data is divided into a plurality of blocks, and a one-page document having blocks that cannot be partially received in the embodiment of the present invention. FIG. 4 is an explanatory diagram illustrating an example of document information.

FIG. 16 shows a state in which one page of document information composed of text data is divided into a plurality of blocks, and one page of one page having a block that could not be received in the embodiment of the present invention. FIG. 9 is an explanatory diagram illustrating another example of the document information.

FIG. 17 is a diagram illustrating a state in which document information for one page composed of graphic data is divided into a plurality of blocks, and a page for one page including blocks that cannot be partially received in the embodiment of the present invention. FIG. 9 is an explanatory diagram illustrating another example of the document information.

FIG. 18 is an explanatory diagram illustrating an example of a transmission pattern of document information in the embodiment of the present invention.

FIG. 19 is an explanatory diagram showing another example of a transmission pattern of document information in the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 viewer system (document information transmission system) 200 transmission device 210 personal computer 230 transmission antenna 240 transmission control unit 250 transmission unit 255 spreader 258 spreading code generator 300 viewer 310 reception antenna 320 Reception unit 323 Despreader 330 Reception control unit 332 Spread code generator 340 Display control unit 341 Storage circuit 350 Display unit 360 Input unit N1, N2, N3 Document information a Block

Claims (8)

[Claims] 1. A document information transmission system comprising: a transmitting device for transmitting document information in which characters or images are recorded in page units; and a receiving device for receiving and displaying the document information transmitted from the transmitting device. The transmitting apparatus may further include a transmitting unit that repeatedly transmits the document information including a plurality of pages at a set transmission speed, and switching between two or more modes for setting different transmission speeds. A transmission control unit for performing control, wherein the receiving device is configured to control at least one of the plurality of pages of document information.
Receiving means for receiving the specified at least one page of document information among the plurality of pages of document information transmitted by the transmitting means; A document information transmission system, comprising: a display unit having a display area capable of simultaneously displaying the document information; and display means for displaying the received document information on the display unit. 2. The transmitting means and the receiving means perform wireless transmission and reception by a spread spectrum method based on a direct spreading method, and the transmission control means comprises: a low-speed mode having a long spreading code length and a low transmission speed; 2. The document information transmission system according to claim 1, wherein the transmission operation of the transmission unit is controlled by switching between a high-speed mode having a short length and a high transmission speed. 3. The document according to claim 1, wherein the transmission control unit controls the transmission operation of the transmission unit by switching the mode in accordance with a preset timing. Information transmission system. 4. The receiving apparatus further includes a determining unit that determines which of the modes the received document information was transmitted in, and the receiving operation of the receiving unit is performed based on the determination result. Claim 1 characterized by the following:
The document information transmission system according to any one of claims 1 to 3. 5. The transmitting means transmits, in addition to the document information, mode information indicating a setting state of the two or more modes, the receiving means receives the mode information, and the determining means The document information transmission system according to claim 4, wherein the determination is performed according to a reception result. 6. A document information transmitting apparatus for transmitting document information in which characters or images are recorded in page units, wherein said transmitting means repeatedly transmits document information comprising a plurality of pages at a set transmission speed. A document information transmission device, comprising: transmission control means for controlling a transmission operation of the transmission means by switching between two or more modes for setting different transmission speeds. 7. The transmitting means performs wireless transmission by a spread spectrum method based on a direct spread method,
The transmission control unit controls a transmission operation of the transmission unit by switching between a low-speed mode having a long spreading code length and a low transmission speed and a high-speed mode having a short spreading code length and a high transmission speed. Item 7. The document information transmitting device according to Item 6. 8. The document information transmission according to claim 6, wherein the transmission unit transmits mode information indicating a setting state of the two or more modes, in addition to the document information. apparatus.