CN1061200C

CN1061200C - Method for adjusting scanning speed of scanner

Info

Publication number: CN1061200C
Application number: CN96109253A
Authority: CN
Inventors: 唐建兴; 黄冠智
Original assignee: Acer Computer Co Ltd
Current assignee: Qisda Corp
Priority date: 1996-07-31
Filing date: 1996-07-31
Publication date: 2001-01-24
Anticipated expiration: 2016-07-31
Also published as: CN1172393A

Abstract

The invention present provides a method for automatically adjusting the scanning speed of a scanner, which can adjust the scanning speed of a scanner according to the data transmission rate between the scanner and a computer for avoiding the problem that an image signal generated by scan is overly accumulated in a memorizer. The method comprises the following steps: a test data package is transferred by the scanner to the computer and timing is started. When the computer receives the data package, the computer notifies the scanner. Transmission time required for the data package is calculated. According to the size and the transmission time of the data packet, the data transmission rate between the scanner and the computer is calculated. According to the data transmission rate, the scanning speed of the scanner is adjusted.

Description

Adjust the method for scanning speed of scanner

The present invention relates to a kind of method of adjusting scanning speed of scanner.

In current office, many file datas often are to import computer with scanner.Common falt bed scanner includes a scan module that is used for optical signalling is converted to analog signal that is installed on the roller bearing usually, the stepper motor that can drive this scan module back and forth, an analog/digital converter is used for this analog signal conversion is become digitized picture signal, the memory of a store images signal, and control unit be used for controlling this scanner all built-in functions and and computer between the communication transmission.

When stepper motor whenever took a step forward, scan module just can convert a thin-line-shaped document image to picture signal and be stored in the memory, and control unit is just passed to computer to the picture signal that is stored in memory and done further processing then.In scanning during a file, what of per unit length interscan line number are decided by the resolution of this scanner.

In general, the message transmission rate between computer and the scanner is decided by the maximum scan speed of employed host-host protocol (transmission protocol), scanner and the reception and the processing speed of computer.If data transmission bauds is faster than the sweep speed of scanner, just scanner can promptly be finished scanning work with maximum speed.If but data transmission bauds is less than sweep speed, just picture signal that then can't instantaneous transmission can be accumulated in the memory.When the picture signal of accumulating surpassed the capacity of memory, stepper motor just must stop to prevent that picture signal from can omit to some extent.After the parts of images signal in the memory was transferred into computer, control unit just can be reset scan module and proceed scanning work from the place that it had before stopped.

Some unsettled phenomenons can take place in several steps of front that just begin to start in stepper motor usually, and this phenomenon might influence the signal quality that scan module is produced when restarting to scan.In order to address this problem, existing at present two kinds of methods are suggested.First method is to allow the reversing of stepping motor that scan module is fallen back several steps backward, and then moves forward scan module again to avoid several steps of unsettled front.The signal that scan module produced during moving forward can't be stored, and when scan module was got back to the position that last time stopped at last, picture signal just can begin to be deposited in memory, and scan module can continue to move forward to finish scanning work then.Though this method has solved the stability problem that scan module is produced when starting, it can make scan module reduce the sweep speed of scanner because of constantly moving around.

Second method is to increase memory span the more images signal can be stored, and therefore scan module just can scan with keeping and avoid being interrupted.Directly strengthen the problem that memory span can very directly alleviate the picture signal accumulation, but it also can increase the complexity of scanner cost and circuit simultaneously.Because the price of DRAM (dynamic random access memory) descends rapidly, add large memories regular meeting and be used as and pay the utmost attention to.But in order to cooperate the use of DRAM, just must add memory refress (refreshing) circuit in the scanner to keep the storage data in it, this makes that the memory circuitry of scanner is complicated more.In addition, increase the problem that memory can not solve the picture signal accumulation veritably.With the color scanner is example, and general color scanner can provide high-resolution coloured image scanning usually, and this scanning can produce very high data traffic and a large amount of picture signals.If just hope that utilize increasing memory solves this problem, the capacity of memory just must be very big, yet whether be ten minutes make us in doubt to the benefit that a large amount of memories can produce if can be directly proportional with the price that it is increased.

Therefore, main purpose of the present invention is to overcome the restriction of aforementioned existing method, provides a kind of method of adjusting scanning speed of scanner to solve above-mentioned problem.

The invention provides a kind of method of adjusting scanning speed of scanner, this scanner is electrically connected on the computer, and this method comprises the following steps: that (1) pass to this computer with a test packet by this scanner and pick up counting; (2) after receiving this packet, this computer notifies this scanner; (3) calculate the used transmission time of this packet; (4) calculate message transmission rate between this scanner and this computer according to size and this transmission time of this packet; (5) adjust the sweep speed of this scanner according to this message transmission rate.

Below in conjunction with accompanying drawing the preferred embodiments of the present invention are described, wherein:

Fig. 1 one is connected to the functional block diagram of the optical scanner on the computer.

Fig. 2 is the flow chart of the program of adjustment scanning speed of scanner provided by the present invention.

Fig. 1 is the functional block diagram of an optical scanner 10 that is connected with computer 12.Scanner 10 includes a scan module 14; A stepper motor 18 is used for accurately driving scan module 14; A control unit 20, be used for gated sweep device 10 all built-in functions and with the communication of computer 12; A memory 22 is connected with control unit 20, is used for storing the picture signal that is produced from scan module 14; And timer 24.In scan module 14, include a charge coupled device 16 (Charge Coupled Device) that is used for scanning the unicursal graph picture.

Fig. 2 is the flow chart of the program 30 of adjustment scanner 10 sweep speeds provided by the present invention.Before a file of scanning, scanner 10 can utilize program 30 to adjust its sweep speed.Program 30 may further comprise the steps: step 31 computer 12 is with sweep parameter such as resolution, and colour or white-black pattern etc. sends scanner 10 to; Step 32 resets scanner 10 with the sweep parameter of receiving; Step 33 is opened timer 24 and is given computer 12 from test packet of scanner 10 transmission; The sweep parameter decision that the length of packet is transmitted by computer 12; Step 34 computer 12 receives and handle packet; Computer 12 receives the method used with handling this test packet and reception and handles the used method of a normal data packet identical; Step 35 is notified scanner 10 behind computer 12 receptions and this packet that disposes; Step 36 stops timer 24 and calculates and transmit the used transmission time of test packet; Step 37 is calculated message transmission rate between scanner 10 and the computer 12 according to the size and the used transmission time of test packet; Step 38 is adjusted the sweep speed of scanner 10 according to message transmission rate; Step 39 begins scanning document with new sweep speed.

Among step 33 and 34, the transmission of test packet and reception are to be handled by scanner 10 and computer 12 parallel synchronous, till this packet is received and disposes.Before the beginning scanning document, scanner 10 utilizes test packet to come message transmission rate between test computer 12 and the scanner 10, but this message transmission rate also can obtain when the general packet of transmission.The user can replace employed test packet in the program 30 obtaining message transmission rate with the packet that generally produces through scanning, and then adjusts the sweep speed of scanner 10 with resultant message transmission rate.

Stepper motor 18 whenever makes a move, and the charge coupled device 16 in the scan module 14 just can sweep a thin-line-shaped document image, so the sweep speed of scanner 10 is decided by the stepping rate that stepper motor 18 drives scan module 14.When calculating the stepping rate of scanner 10, at first to calculate and produce the needed number of scanning lines of test packet, the stepping rate of stepper motor 18 just can be tried to achieve by this number of scanning lines and the transmission time that this test packet consumed then.

When the stepping rate of decision stepper motor 18, there is a factor will consider, that is exactly the stationary problem of stepper motor 18 and charge coupled device 16.Charge coupled device 16 constantly detects received reflection ray with a predetermined photosensitive cycle.After each photosensitive cycle, charge coupled device 16 can be exported in the mode of analog signal by the aanalogvoltage that the analog memory in it is stored in proper order, and then with the analog memory zero clearing to prepare next sensitization.If the photosensitive cycle of the stepping rate of stepper motor 18 and charge coupled device 16 is synchronous, then will becomes and be very easy to control from charge coupled device 16 taking-up data.Setting up one of method synchronous between stepper motor 18 and the charge coupled device 16, exactly stepper motor 18 to be moved the needed time set that moves a step be the integral multiple of the photosensitive cycle of charge coupled device 16, so just can finish the Synchronization Control between stepper motor 18 and the charge coupled device 16 at an easy rate.

Handling procedure 30 can use with decision under many different situations and set up the suitable sweep speed of scanner 10, generally is suggestion executive program 30 before a file of scanning, because it need only want tens of microseconds just can finish usually.So Duan time should be discovered concerning the user.Program 30 not only can be avoided the shortcoming of two kinds of existing methods as mentioned above, and also provides a kind of very effective and cheap method to solve the problem of above-mentioned scanner picture signal accumulation.

Claims

1, a kind of method of adjusting scanning speed of scanner, this scanner is electrically connected on the computer, and this method comprises the following steps:

(1) test packet is passed to this computer by this scanner and pick up counting;

(2) after receiving this packet, this computer notifies this scanner;

(3) calculate the used transmission time of this packet;

(4) calculate message transmission rate between this scanner and this computer according to size and this transmission time of this packet;

(5) adjust the sweep speed of this scanner according to this message transmission rate.

2, the method for claim 1 comprising the one scan module, is used for scanning document; One stepper motor is used for driving this scan module in the mode of stepping; And the sweep speed of this scanner is to be decided by the stepping rate that this stepper motor drives this scan module.

3, method as claimed in claim 2 wherein, at first calculates and produces the required number of scanning lines of this packet, and this stepping rate was decided by this number of scans and this transmission time then.

4, method as claimed in claim 3, wherein, this scan module comprises: a charge coupled device, and it constantly detects received reflection ray with a predetermined photosensitive cycle, and this stepping rate is adjusted to the photosensitive cycle of this charge coupled device synchronous.

5, method as claimed in claim 4, wherein, this stepper motor moves the integral multiple that the needed time that moves a step is set to this photosensitive cycle.

6, the method for claim 1, wherein scanning one file before, this scanner utilizes this method to adjust its sweep speed.

7, the method for claim 1, wherein before this scanner begins to transmit this packet, this computer sends a plurality of sweep parameters to this scanner to reset this scanner.

8, method as claimed in claim 7, wherein, the length of this test packet is determined by this sweep parameter.

9, the method for claim 1, wherein this computer to receive, handle the used method of the used method of this test packet and reception, processing one normal data packet identical.