CN1367606A - Different colour channel output method of balanced colour sensor - Google Patents

Abstract

An output method of different colour passage for balance colour transducer can be used for the colour transducer with several colour passages, which the output method creates several transmission gate signals corresponding to abovesaid several colour passages at different times and these transmission gate signals will locate in the same section with phase position signal. In addition, each their own output time of these colour passages can have the same midpoint or have different periods of shade opening time separately. The present invention is not easy creating colour difference, simple in circuit design and can be suitably used in existing vedio sensing system.

Description

The different color channels output intent of balance color sensor

The present invention relates to a kind of output intent of color sensor, particularly a kind of different color channels output intent of balance color sensor.

Copying machines, facsimile machine and scanner etc. convert visual pattern in the image conversion apparatus of suitable electronic form for printing, storage, transmission or other electronic applications to, the general optical sensor that uses, for example: charge coupled cell (charge couple device, CCD) or the contact image sensor (contactimage sensor CIS) waits the sensing that carries out image.And for colour imaging, these optical sensors are commonly rearranged with the CCD element line of three kinds of colors of red, green, blue.Usually, all CCD element line all can expose after one period set time the charge transfer that will induce to analogue shift register and carry out follow-up processing again.

In general, light intensity changes along with the different of system with CCD sensitivity meeting, even, different along with the variation of time in a system probably.And for each Color Channel (red, green, basket), its CCD sensitivity is also different separately, and the maximum light intensity that can respond to and minimum light intensity are also different naturally.Therefore, for its noise specific energy of signal that makes the light sensing gained reaches maximum, just must give the adjustment of different variablees to each Color Channel.These variablees that can be adjusted comprise light intensity, CCD time for exposure at least, and the gain of signal amplifier or the like.

A kind of practice in the prior art is that the time span that simple adjustment shade (shutter) covers is with different purpose of the time for exposure that reaches each Color Channel.Please refer to Fig. 1, its demonstration be exactly the sequential chart of this technology.Wherein, signal sh1, sh2 and sh3 are respectively three kinds of employed transmission gate signals of Color Channel.And signal shutter1, shutter2 and shutter3 then represent the initial and concluding time of shade (shutter) signal of three kinds of Color Channels respectively.Signal PH1 and PH2 then are the employed phase signals of CCD element.As can be seen from Figure, in this technology, though can obtain Signal-to-Noise preferably because time for exposure of each color is different, the time that its each Color Channel exposes simultaneously concentrates on the back segment of overall exposing time.Such mode can relatively be easy to generate aberration.

No. the 324076th, Republic of China's patent announcement, in the patent of title for ' improving the method for the Signal-to-Noise of the ccd sensor in the color image forming apparatus ', also mention a kind of method of adjusting signal to noise ratio.In this method, to the time for exposure of different Color Channel use different lengths, so that the Signal-to-Noise maximization.Though this kind method seems simply, and the difficulty of execution is arranged actually.For instance, the cycle that employed transmission gate signal (SH) has different time length in same Color Channel exists, promptly the interpulse period of its transmission gate signal different in size, right and wrong length of single regular time.Just in this respect, the design of its phase signal will be very difficult.Therefore, the design cost of the circuit of generation phase signal will increase.

In sum, prior art has following shortcoming:

1. be easy to generate aberration.2. circuit design is difficult for, and causes the increase of manufacturing cost.

In view of this, the object of the present invention is to provide a kind of method of different color channels output of balance color sensor.

The method of the different color channels output of balance color sensor of the present invention, be applicable in the scanner with a plurality of Color Channels, it is characterized in that, different time produces a plurality of transmission gate signals that correspond respectively to these a plurality of Color Channels, and these a plurality of transmission gate signals are arranged in phase signal and have same section of same magnitude of voltage.

Described a plurality of Color Channel output time separately has same mid point.

Described a plurality of Color Channel has the shade start-up time of different length respectively.

Effect of the present invention is: the method for the different color channels output of balance color sensor proposed by the invention, not only be difficult for producing aberration, and also comparatively simple aspect circuit design, among present image sensing system.

Below be simple declaration to accompanying drawing of the present invention:

Fig. 1 is the sequential chart of prior art; And

Fig. 2 is the sequential chart of a preferred embodiment of the present invention.

The present invention is described in detail below in conjunction with accompanying drawing.

Please refer to Fig. 2, be a kind of sequential chart of a preferred embodiment of the present invention.Generally speaking, (charge couple device CCD) is made up of several CCD element lines colour charge coupling element, and wherein each row can a kind of color of sensing.With regard to the operating mode of single CCD element line, when the voltage of transmission gate signal (as: sh1) once changed up and down, the electric charge that this CCD element line is sensed will move in the displacement buffering area (shift buffer) by transmission gate.And move on to the electric charge of displacement in the buffering area, can be according to the design requirement of system, in the variation in voltage of phase signal (PH1 or PH2), be displaced to gradually in the A/D converter (A/D converter), being converted to digital voltage signal by the analog voltage signal that electric charge was caused.

Because when the voltage of phase signal changes to some extent, the electric charge of displacement in the buffering area will be according to the design of system and the position at mobile place, therefore, electric charge in the CCD element line just must just can not carry out in the change at phase signal if will move in the displacement buffering area by transmission gate.In the present embodiment, signal sh1, sh2 and sh3 are high potential at phase signal PH1, and phase signal PH2 produces (that is, the variation up and down of voltage is arranged) in same section of electronegative potential.Therefore, each electric charge that is listed as in the CCD element line also can move in the displacement buffering area by transmission gate at this moment.Should be noted that, though present embodiment is when phase signal PH1 is high potential, electric charge in the CCD element line is moved in the displacement buffering area, but different requirements along with system design, can certainly when phase signal PH1 is electronegative potential, the electric charge in the CCD element line be moved in the displacement buffering area.

In the present embodiment, different from the past is with the employed transmission gate signal of each CCD element line sh1, and sh2 produces at different time points respectively with sh3.These transmission gate signals then are to be arranged in the same section that phase signal has same magnitude of voltage.Such practice is in order to make that the output frequency of the electric charge that three kinds of Color Channels (channel) are responded to can be consistent designed.And after each transmission gate signal changed on voltage to some extent, shade (shutter) will start a period of time with the unnecessary charge inducing of cancellation.With first Color Channel is example, and its employed transmission gate signal is sh1, and phase signal is PH1 and PH2, and then be shown among the matte signal shutter1 start-up time of shade.Wherein, so-called shade is exactly the rising edge of matte signal shutter1 and the time section between trailing edge start-up time.According to shown in Figure 2, then Shi Ji exposure section is exactly the hatched example areas that is positioned under the matte signal shutter1.Equally, the actual exposure section of second Color Channel is the hatched example areas that is positioned under the matte signal shutter2, and the actual exposure section of the 3rd Color Channel then is the hatched example areas that is positioned under the matte signal shutter3.

Because each row CCD element line may be different to the sensitivity of the luminous intensity that received, so at just can effectively the further upper limit of the luminous intensity that each Color Channel received of the actual exposure section of each row CCD element line design different length.In the present invention, be exactly the transmission gate signal that produces by different time (sh1, sh2, sh3) and the length shade that differs reach this purpose start-up time.And in the present embodiment, the overlapping part of actual exposure section is than the stage casing zone of the overlapping part of actual exposure section among Fig. 1 near the overall exposing time as can be seen.Therefore, the present invention can more reduce the generation of aberration phenomenon.Though and in the present embodiment, the center line of actual exposure section is identical, this and non-limiting the present invention only can use in this case.

Because it is too many that the present invention does not change on signal, only be to elongate the fixed time of phase signal, and general's other transmission gate signal generated in the different time, so on circuit design, can be easy to reach, not need the complicated circuit of special design because will realize the present invention.

Claims (4)

1. the different color channels output intent of a balance color sensor, be applicable in the scanner with a plurality of Color Channels, it is characterized in that, different time produces a plurality of transmission gate signals that correspond respectively to these a plurality of Color Channels, and these a plurality of transmission gate signals are arranged in phase signal and have same section of same magnitude of voltage.

2. the different color channels output intent of balance color sensor as claimed in claim 1 is characterized in that, these a plurality of Color Channels output time separately has same mid point.

3. the different color channels output intent of balance color sensor as claimed in claim 1 is characterized in that, these a plurality of Color Channels have the shade start-up time of different length respectively.

4. the different color channels output intent of balance color sensor as claimed in claim 3 is characterized in that, these a plurality of Color Channels output time separately has same mid point.