CN1641684A

CN1641684A - Control device and method for image scanning system

Info

Publication number: CN1641684A
Application number: CN 200410001477
Authority: CN
Inventors: 张辉煌; 洪岳农; 黄泉龙; 黄皓祥
Original assignee: Realtek Semiconductor Corp
Current assignee: Realtek Semiconductor Corp
Priority date: 2004-01-08
Filing date: 2004-01-08
Publication date: 2005-07-20

Abstract

The invention supplies a control device for image scanning system and the method. The system comprises a direct current motor and an image sensor. The motor is used to drive the sensor to move. A location signal represents the correlative location of the sensor. The operation of the control device and the control method is based on the location signal.

Description

The control device of image-scanning system and control method

Technical field

The present invention relates to a kind ofly, particularly relate to control device and method the image scanning system that disposes a direct current motor in order to control the device and method of an image-scanning system (Image scanning system).

Background technology

In the known image-scanning system, image sensor is under the driving of step motor (Stepping motor), and then linearly scanning document is carried out image sensing (scanning).For a control device control step motor, phase place of this control device output, step motor just can be realized the feeding of a micro-stepping.Because this control device knows and exported what phase places, know that just this step motor is just changeing or reverses several micro-steppings.In other words, what phase places this control device by having exported, as can be known by the relative position of the image sensor of step motor institute transmission.When this control device is known the relative position of this image sensor, the i.e. time shutter of this image sensor of may command.When this control device drives step motor under with the situation of fixed drive speed, represent this image sensor to move with fixed rate.

About the above-mentioned control timing of utilizing the image sensor of step motor driving, see also shown in Figure 1.Fig. 1 shows the correlation timing figure that triggers the image sensor effect.(Contact Image Sensor CIS) comprises three color channels (Color channels) to typical contact image sensor, is respectively a redness, a green and blue color channel.

As shown in Figure 1, being used for the start signal SS of sensing image in order to trigger contact image sensor (CIS), is to occur initial pulse (Start pulse) SP at interval with a regular time.Initial pulse SP among the start signal SS is used for triggering in regular turn each color channel effect of this contact image sensor, and then sensing is about the data of image.Be shown in Fig. 1 equally,

label

12,14 and 16 is controlled the control signal of redness, green and the blue LED (LED) of this contact image sensor respectively.The image data that contact image sensor sensed is read subsequently in regular turn, reads (Read-out) sequential 18 as Fig. 1.Read sequential 18 reads the image data of this contact image sensor for this control device time point.(news are similar during to the control of above-mentioned contact image sensor for ChargeCoupled Device, control timing CCD), do not do at this and give unnecessary details about the Charged Coupled Device sensor that utilizes step motor to drive.

Yet,, need the enough big step motor of torsion along with the sweep velocity to scanner requires to improve.But its volume is also bigger usually for the big step motor of torsion, then can't satisfy light, thin, short, the little requirement of scanner.If use d.c. motor to replace step motor, because the position control of d.c. motor is than the step motor difficulty.Replacing under the prerequisite of step motor with d.c. motor, how to carry out the sequential control mechanism of position control and image sensor, quite important for the quality of scan-image.

Summary of the invention

Therefore, a purpose of the present invention provides a kind of device and method of controlling an image scanning system, and this image scanning system comprises a direct current motor and an image sensor, and this d.c. motor is in order to drive moving of this image sensor.

According to a preferred embodiment of the present invention, during the moving of this image sensor, on behalf of the position signalling of the relative position of this image sensor, one produced.Control device according to the present invention comprises a clock control logic.This clock control logic is based on this position signalling, in order to produce an initial pulse and a plurality of exposure signal.This clock control logic and export at least one signal that reads to this image sensor is in order to read the image scan data that this image sensor is exported.This initial pulse is represented a horizon scan line cycle initial of this image sensor.

According to another preferred embodiment of the present invention, this control device further comprises a timer.This timer is in order to a time interval in this horizon scan line cycle of timing.

According to another preferred embodiment of the present invention, this control device further comprises a decision logic.Whether this decision logic is in order to a position signalling only occurring between the initial pulse of judging this initial pulse and continuing, and if judged result for certainly, determines the image scan data in data represented this horizon scan line cycle of this image scan.

Can be further understood by following detailed Description Of The Invention and institute's accompanying drawing about the advantages and spirit of the present invention.

Description of drawings

Fig. 1 is the correlation timing figure of known triggering image sensor effect;

Fig. 2 A is the synoptic diagram of using according to its peripheral matable assembly of timing unit of the present invention or circuit;

Fig. 2 B is the synoptic diagram of position signalling PS among Fig. 2 A.This position signalling PS presents a plurality of P-pulse PP;

Fig. 3 A is the relevant control timing figure according to first pattern of the present invention;

Fig. 3 B is the relevant control timing figure according to three-mode of the present invention;

Fig. 4 A is the sequential chart according to an example of the relevant control timing of the second preferable preferred embodiment of the present invention;

Fig. 4 B is the relevant control timing figure according to four-mode of the present invention; With

Fig. 5 is the relevant control timing figure according to the 5th pattern of the present invention.

The reference numeral explanation

SS: start signal SP: initial pulse

12,14,16,322,324,326: exposure signal

18, RC: readout clock signal R, G, B, R/G/B: readout clock

20: optics chi 22: optical encoder

24: position code translator 28: image sensor

26: time sequence control logic 30: analog-to-digital converter

PS: position signalling PP: P-pulse

32: bus 2: control device

44: buffer 34: storer

EX: exposure signal TICNT: time interval accumulated signal

T1-T6: time interval RESET: replacement clock

Embodiment

Ask for an interview shown in Fig. 2 A about using peripheral matable assembly according to the present invention.About the position probing of image sensor, can adopt an optics chi (Encoder strip) 20 and cooperate an optical encoder 22.Can provide a yardstick on the general optics chi 20, with foundation as follow-up resolution.For example, the yardstick that provides on the optics chi 20 is 1/150 inch, with the foundation as follow-up resolution 150dpi.This optical encoder 22 can transmit a signal PHA and signal PHB to a position code translator 24.Wherein, this signal PHA and this signal PHB differ 1/4 phase place.Position code translator 24 with the signal PHA that received and signal PHB after treatment, a position signalling PS of its output can provide the foundation of 600dpi resolution, its correlation technique can be with reference to United States Patent (USP) 4,639,884.Fig. 2 A is the category of a control device with the mac function 2 that dotted line was indicated.

Note shown in Fig. 2 B that P-pulse PP occurred with revocable time interval among this position signalling PS, promptly react this image sensor 28 and driven by d.c. motor.

Several preferable preferred embodiment of the present invention below will be described in detail in detail, use abundant explanation feature of the present invention, spirit and advantage.

Be that explanation is done in the sequential control of contact image sensor (CIS) at first at image sensor.Ask for an interview shown in Fig. 2 A and Fig. 3 A, in a preferred embodiment, this time sequence control logic 26 is that to have a CIS of three color channels at the typical case designed, and its relevant control timing is asked for an interview shown in Fig. 3 A.Hereinafter to be referred as this preferred embodiment is first pattern.As shown in Figure 3A, time sequence control logic 26 is controlled by each the P-pulse PP among this position signalling PS, and then produces three initial pulse SP, three clock signals (also claiming exposure signal) (label 322,324,326) and three readout clocks (R, G and B).Respond to image by red LED, green LED and blue led that the clock on the clock signal 322 of time sequence control logic 26 output, clock on the clock signal 324 and the clock on the clock signal 326 are lighted this CIS28 in regular turn.This time sequence control logic 26 and export corresponding readout clock simultaneously outputs to an analog-to-digital converter (ADC) 30 with the data that sensed, and numeral is after be passed to a storer 34 by a bus 32.Note that in first pattern, very first time interval T 1 equals second time interval T2.As for the 3rd time interval T3 then is revocable time interval.The corresponding time interval T2 of clock on the clock signal 322, and in time interval T2, finish.The corresponding time interval T3 of clock G, and in time interval T3, finish.Clock B is the corresponding next time interval T1 of the clock system on the signal 324, and finishes in this time interval T1.In first pattern, because this image sensor is contact image sensor (CIS), its clock signal (exposure signal) (322,324 and 326) goes up the time length of clock and can be controlled by this time sequence control logic 26, so the time interval of T1, T2, T3 is inequality, little to the image quality influence, can be applicable to the higher scanning system of rate request.

In another preferred embodiment, please refer to Fig. 3 B, be second pattern hereinafter to be referred as this preferred embodiment.Note, all equal at the very first time interval T shown in Fig. 3 B 1, second time interval T2 and the 3rd time interval T3.As for be positioned at the 4th initial pulse SP after the 4th time interval T4 then for revocable time interval.The time length that the clock signal (exposure signal) (322,324 and 326) that second pattern is provided goes up clock is then identical, and the time interval of T1, T2, T3 is also identical, can be applicable to the scanning system that image quality is had relatively high expectations.

Be that explanation is done in the sequential control of Charged Coupled Device sensor (CCD) then at image sensor, ask for an interview shown in Fig. 4 A, the relevant control timing shown in Fig. 4 A is in order to describe clock signal and the relevant clock signal that is used for assisting CCD28 control that triggers a CCD28.

Hereinafter to be referred as this preferred embodiment is three-mode.Time sequence control logic 26 provides the fixing time shutter as second pattern.Shown in Fig. 4 A, time sequence control logic 26 is controlled by each the P-pulse PP among this position signalling PS, and then produces two initial pulse SP.First initial pulse SP is used for triggering the CCD28 effect, expose, and then sensing is about being scanned the image data of object.About the clock signal of CCD28 exposure control, ask for an interview among Fig. 4 A shown in the label EX.The data that CCD28 sensed are passed to buffer 44 at once.Note, in three-mode, very first time interval T 1 between first initial pulse SP and second initial pulse SP is for fixing, and is revocable at second initial pulse SP with second time interval T2 between inferior first initial pulse SP.Shown in Fig. 4 A, behind time sequence control logic 26 this second initial pulse of output SP, export readout clock R/G/B immediately.The signal of carrying clock R/G/B is the signal RC shown in Fig. 4 A.During clock R/G/B, be stored in data jump in the buffer 44 to storer 46.In the present embodiment, can during very first time interval T 1, export a replacement clock RESET and do self replacement in order to trigger CCD28.

In another preferred embodiment, time sequence control logic 26 is to provide revocable time shutter designed at typical C CD, and its relevant control timing is asked for an interview shown in Fig. 4 B.Hereinafter to be referred as this preferred embodiment is four-mode.Shown in Fig. 4 B, the clock that occurs among the signal EX is represented the length of CCD28 time shutter, and is directly determined by the time interval between the two adjacent initial pulse SP.Therefore, length and the on-fixed of CCD28 time shutter each time.Shown in Fig. 4 B, at first the time interval T1 of Chu Xianing is also unequal with the time length of the time interval T2 that is right after appearance.In four-mode, this control device 2 further comprises a counter (not being shown among the figure).This counter is in order to calculate and to store the time interval between the adjacent initial pulse SP of two-phase, the label TICNT of the signal that it went out shown in Fig. 4 B.Time interval T1 and time interval T2 that on behalf of the technology device, label T1 on the signal TICNT and T2 promptly calculated.Four-mode and according to the length of exposure time interval is done linear compensation to this image data.

Certainly also can not control the exposure of this image sensor and read sequential, please refer to Fig. 5 (the 5th pattern) according to this position signalling PS.This time sequence control logic 26 this start signal of output SS, wherein the time interval of initial pulse SP is fixing, that is time interval T1-T6 as shown in Figure 5, the time length in its time interval is all equal, and the time length of each clock among the sequential signal EX is all unanimity in real time.Because the time interval of this position signalling PS then is revocable.In the 5th pattern, this controller 2 further comprises a decision logic (not being shown among the figure).Whether P-pulse SP appears in this decision logic judgement time in the time interval between each initial pulse SP and its initial pulse SP that continues.When the result of above-mentioned judgement was sure, the image data of corresponding this constant duration then was accepted, and for example, the image data of time interval T1, T2, T4 and T5 is accepted in the corresponding diagram 5.When the result of above-mentioned judgement is negative, this decision logic will be regarded as the image data of same horizontal scanning line, and then the image data of corresponding this constant duration is then cast out, and for example, the image data of time interval T3 and T6 system is cast out in the corresponding diagram 5.

According to the time sequence control logic and the relevant control timing flow process of five kinds of patterns provided by the present invention, environment that it was suitable for and the operation that meets require to list in table one.

Table one

Pattern	The image sensor that is suitable for	The scan-image quality	Sweep velocity
Pattern	The image sensor that is suitable for	The scan-image quality	Sweep velocity	First pattern	????CIS	Good	Fast
Second pattern	????CIS	Good than first pattern	Than the sweep time of first pattern increase by 1/3	First pattern	????CIS	Good	Fast
Second pattern	????CIS	Good than first pattern	Than the sweep time of first pattern increase by 1/3	Three-mode	????CCD	Good than fourth, fifth pattern	Slow than the 5th pattern
Four-mode	????CCD	Good	Slow than the 5th pattern	Three-mode	????CCD	Good than fourth, fifth pattern	Slow than the 5th pattern
Four-mode	????CCD	Good	Slow than the 5th pattern	The 5th pattern	????CCD	Good	Fast

Listed data in the table one are enough to confirm control device provided by the present invention and method, have its practicality.

By the above detailed description of preferred embodiments, be to wish to know more to describe feature of the present invention and spirit, and be not to come category of the present invention is limited with above-mentioned disclosed preferred embodiment.On the contrary, its objective is that hope can contain in the category that is arranged in claim of the present invention of various changes and tool equality.

Claims

One kind control one image-scanning system method, this device of image scanning comprises a direct current motor and an image sensor, this d.c. motor is in order to drive moving of this image sensor, and a position signalling is represented the relative position of this image sensor, and this method comprises the following step:

Based on this position signalling, export an initial pulse to this image sensor, this initial pulse is represented a horizon scan line cycle initial of this image sensor;

During this horizon scan line cycle:

Export at least one exposure signal to this image sensor; And

Read the image scan data that this image sensor is exported.
2. the method for claim 1, wherein this image sensor is a contact image sensor, this exposure signal is exported in regular turn.
3. method as claimed in claim 2, wherein these a plurality of exposure signals are lighted the corresponding light emitting diode of this contact image sensor respectively.
4. the method for claim 1, wherein this image sensor is a Charged Coupled Device sensor, this exposure signal is to export simultaneously.
5. the method for claim 1, wherein a plurality of exposure signal steps of this output are further carried out:

Export at least one pulse signal to this image sensor, identical in fact with the time shutter of guaranteeing this image sensor.
6. control device as claimed in claim 5, wherein this at least one pulse signal is three pulse signals, and is identical in fact with the redness of guaranteeing this image sensor, green and blue time shutter.
7. the method for claim 1 wherein further comprises:

Based on this position signalling, a time interval in this horizon scan line cycle of timing.
8. method as claimed in claim 7, wherein should the time interval in order to compensate these image scan data in this horizon scan line cycle.
One kind control one image-scanning system method, this image-scanning system comprises a direct current motor and an image sensor, this d.c. motor is in order to drive moving of this image sensor, and a position signalling is represented the relative position of this image sensor, and this control method comprises the following step:

Export an initial pulse to this image sensor, this initial pulse is represented a horizon scan line cycle initial of this image sensor;

Export at least one exposure signal to this image sensor;

Read the image scan data that this image sensor is exported; And

Whether only occur a position signalling between the initial pulse of judging this initial pulse and continuing, and if judged result for certainly, determines the image scan data in data represented this horizon scan line cycle of this image scan.
10. method as claimed in claim 9, wherein this image sensor is a Charged Coupled Device sensor, this exposure signal is to export simultaneously.
A 11. control device that supplies an image-scanning system to use, this image-scanning system comprises a direct current motor and an image sensor, this d.c. motor is in order to drive moving of this image sensor, and a position signalling is represented the relative position of this image sensor, and this control device comprises:

One clock control logic, this clock control logic based on this position signalling in order to produce an initial pulse and at least one exposure signal, this clock control logic and export at least one signal that reads to this image sensor is in order to read the image scan data that this image sensor is exported;

Wherein, this initial pulse is represented a horizon scan line cycle initial of this image sensor.
12. control device as claimed in claim 11, wherein this image sensor is a contact image sensor, and this exposure signal is to export in regular turn.
13. control device as claimed in claim 12, wherein these a plurality of exposure signals are corresponding light emitting diodes of lighting this contact image sensor respectively.
14. control device as claimed in claim 11, wherein this image sensor is a Charged Coupled Device sensor, and this exposure signal is to export simultaneously.
15. control device as claimed in claim 11, wherein this control device is exported at least one pulse signal to this image sensor, and is identical in fact with the time shutter of guaranteeing this image sensor.
16. control device as claimed in claim 15, this at least one pulse signal are three pulse signals, and be identical in fact with the redness of guaranteeing this image sensor, green and blue time shutter.
17. control device as claimed in claim 11, wherein this control device further comprises:

One timer, this timer is in order to a time interval in this horizon scan line cycle of timing.
18. control device as claimed in claim 17, wherein these image scan data in this horizon scan line cycle are to do compensation according to the count value of this timer.
A 19. control device that supplies an image-scanning system to use, this image-scanning system comprises a direct current motor and an image sensor, this d.c. motor is in order to drive moving of this image sensor, and a position signalling is represented the relative position of this image sensor, and this control device comprises:

One clock control logic, this clock control logic is in order to produce an initial pulse and at least one exposure signal, this clock control logic and export at least one signal that reads to this image sensor is in order to read the image scan data that this image sensor is exported;

Whether one decision logic, this decision logic be in order to a position signalling only occurring between the initial pulse of judging this initial pulse and continuing, and if judged result for certainly, determines the image scan data in data represented this horizon scan line cycle of this image scan.