TWI416951B - Sensing devices - Google Patents

Description

Sensing device

The present invention relates to a sensing device, and more particularly to a sensing device that triggers three primary color light sources to emit light in a specific order, and stores signals obtained by sensing three primary colors by a buffer having two storage columns. The signal read by the register is made to have a Bayer Pattern data format.

Existing line sensing devices operate during successive sensing periods to sense images of the target. In the prior art, during each sensing period, the driving unit of the sensing device drives the red light source, the green light source, and the blue light source once to emit red light, green light, and blue light to the target, respectively. The sensing unit of the sensing device generates a plurality of red signals, a plurality of green signals, and a plurality of blue signals according to the light that the target is illuminated by the red light, the green light, and the blue light.

General Image Processing Chips Most image sensors use a data format called the Bayer pattern. The data format of the so-called Bell diagram means that the data is divided into two consecutive groups, one of which is a complex arrangement of a plurality of red signals and a plurality of green signals, and another group of which is a complex arrangement of a plurality of green signals and a plurality of blue signals. Therefore, when the line sensing device is applied to the digital image processing device, the reading unit at the back end receives the plurality of red signals, the plurality of green signals, and the plurality of blue signals from the sensing device, and is arranged through a complicated program. The configuration order of the red signal, the green signal, and the blue signal is such that the signal configuration conforms to the Belle file data format.

The present invention provides a sensing device for operating during a plurality of consecutive sensing periods, including a red illumination source, a green illumination source, a blue illumination source, and a drive unit. The driving unit simultaneously drives the red light source, the green light source, and the blue light source to respectively emit a red light, a green light, and a blue light to the target. During each sensing period, the driving unit drives the green light source twice, drives the red light source once, and drives the blue light source once.

In some embodiments, during each sensing period, the drive unit sequentially drives the red illumination source once, drives the green illumination source twice, and drives the blue illumination source once.

The sensing device of the present invention further includes a sensing unit and a register having two storage columns. The sensing unit generates a plurality of red signals, a plurality of first green signals, a plurality of second green signals, and a plurality of blue signals according to the light reflected by the target being illuminated by the red light, the green light, and the blue light. The register is configured to store the red signals, the first green signals, the second green signals, and the blue signals or the red signals, the first green signals, and the second The green signal, and the derivative signals of the blue signals. By controlling the write and read sequence of the scratchpad, the signal read from the scratchpad has a Bayer Pattern data format.

The above described objects, features and advantages of the present invention will become more apparent from the description of the appended claims.

Figure 1 is a diagram showing a sensing device in accordance with an embodiment of the present invention. Referring to FIG. 1, the sensing device 1 includes a red light source RL, a green light source GL, a blue light source BL, a light guide plate 10, a columnar lens 11, a sensing unit 12, a driving unit 13, and a reading unit 14. The sensing unit 12 has a plurality of sensing cells 120 _{1 -} 120 _N . The driving unit 13 drives the red light source RL, the green light source GL, and the blue light source BL through the drive signals SR, SG, and SB, respectively. When the sensing device 1 senses the influence of a target, the sensing device 1 operates during a plurality of consecutive sensing periods. During each sensing period, the driving unit 13 drives the red light source RL, the green light source GL, and the blue light source BL through the driving signals SR, SG, and SB at different times to respectively emit red light and green light through the light guide plate 10. And blue light to the target 15. The sensing unit 12 generates a corresponding signal according to the target 15 being irradiated with red light, green light, and blue light.

According to an embodiment of the present invention, in each sensing period, the driving unit 13 drives the red light source RL once, the green light source GL twice, and the blue light source BL at a time. However, the order in which the driving unit 13 drives the red light source RL, the green light source GL, and the blue light source BL is determined according to system requirements, and the driving unit 13 is not limited to driving the green light source GL twice in succession. According to the embodiment of FIG. 2, in each sensing period, the driving unit 13 sequentially drives the red light source RL once, the green light source GL twice, and the blue light source BL as an example. Wherein, the driving unit 13 drives the green light source GL twice in succession. In Fig. 2, "LED_R" indicates the light-emitting state of the red light source RL, wherein the period marked by the oblique line is a period during which the red light source RL is driven by the driving unit 13 to emit red light; "LED_G1" and "LED_G2" indicate The light-emitting state of the green light source GL, wherein the period marked by the oblique line of the LED_G1 is the period during which the green light source GL is driven by the driving unit 13 for the first time to emit green light during each sensing period, and the period marked by the oblique line of the LED_G2 During each sensing period, the green light source GL is driven by the driving unit 13 for a second time to emit green light; "LED_B" indicates the light emitting state of the blue light source BL, wherein the period marked by the oblique line is a blue light source The BL is driven by the driving unit 13 to emit blue light. As can be seen from FIG. 2, the driving unit 13 drives the red light source RL, the green light source GL, and the blue light source BL in the order of driving the red light source RL once, then driving the green light source GL for the first time, and then the second time. The green light source GL is driven, and finally the blue light source BL is driven once.

Referring to Figures 1 and 2, "SIG" indicates the signal transmission state from the sensing unit 12 to the reading unit 14. The operation of the driving unit 13 in the sensing period DT1 will be described below as an example. During the sensing period DT1, when the driving unit 13 drives the red light source RL to emit red light to the target 15, the target 15 reflects the red light, and the sensing cells 120 _{1 -} 120 _{N of} the sensing unit 12 sense The red light is reflected back, and the complex red signal AR1-ARn is generated by the sensing unit 12. The sensing unit 12 then outputs the red signals AR1-ARn to the readout unit 14 in accordance with the pulse wave P _{R1 of the} trigger signal FS. In FIG. 2, the period indicated by Vout_R in the signal transmission state "SIG" indicates a period during which the sensing unit 12 outputs the red signals AR1-ARn to the reading unit 14.

In the sensing period DT1, after the driving unit 13 finishes driving the red light source RL, the driving unit 13 drives the green light source GL to emit green light to the target 15 for the first time. At this time, the target 15 reflects the green light, and the sensing cells 120 _{1 -} 120 _{N of} the sensing unit 12 sense the reflected green light, and the sensing unit 12 generates the complex first green signal AG11-AG1n. . The sensing unit 12 then outputs the first green signals AG11-AG1n to the readout unit 14 in accordance with the pulse wave P _{G11 of the} trigger signal FS. In FIG. 2, the period marked by Vout_G1 in the signal transmission state "SIG" indicates that the sensing unit 12 outputs the first green signal AG11-AG1n generated by the driving unit 13 for the first time to drive the green light source GL to the readout. The period of unit 14.

In the sensing period DT1, after the driving unit 13 finishes driving the green light source GL for the first time, the driving unit 13 drives the green light source GL to emit green light to the target 15 for the second time. At this time, the target 15 reflects the green light, and the sensing cells 120 _{1 -} 120 _{N of} the sensing unit 12 sense the reflected green light, and the sensing unit 12 generates the complex second green signal AG21-AG2n. . The sensing unit 12 then outputs the second green signal AG21-AG2n to the readout unit 14 according to the pulse wave P _{G21 of the} trigger signal FS. In FIG. 2, the period marked by Vout_G2 in the signal transmission state "SIG" indicates that the sensing unit 12 outputs the second green signal AG21-AG2n generated by the driving unit 13 for the second time driving the green light source GL to the readout. The period of unit 14.

Next, in the sensing period DT1, after the driving unit 13 completes the second driving of the green light source GL, the driving unit 13 drives the blue light source BL to emit blue light to the object 15. At this time, the target 15 reflects the blue light, and the sensing cells 120 _{1 -} 120 _{N of} the sensing unit 12 sense the blue light reflected back, and the complex blue signals AB1-ABn are generated by the sensing unit 12. The sensing unit 12 then outputs the blue signals AB1-ABn to the readout unit 14 in accordance with the pulse wave P _{B1 of the} trigger signal FS. In FIG. 2, the period indicated by Vout_B in the signal transmission state "SIG" indicates a period during which the sensing unit 12 outputs the blue signals AB1-ABn to the reading unit 14.

Referring to FIG. 3, the readout unit 14 includes an analog-to-digital converter 30 and a register 31, wherein the register 31 has a first storage column 310 and a second storage column 311. Referring also to FIGS. 1 and 3, the analog-to-digital converter 30 separates the red signal AR1-ARn, the first green signal AG11-AG1n, the second green signal AG21-AG2n, and the blue signal AB1-ABn from the detecting unit 12, respectively. Converted to a digital format to generate a complex digital red signal DR1-DRn, a complex first digital green signal DG11-DG1n, a complex second digital green signal DG21-DG2n, and a complex digital blue signal DB1-DBn, respectively.

Referring to FIG. 2, in the first storage period between the pulse waves P _R1 and P _G21 of the trigger signal FS, the detecting unit 12 sequentially outputs the red signal AR1-ARn and the first green signal AG11-AG1n. . Therefore, during the first storage period ST1, the digital red signals DR1-DRn corresponding to the red signals AR1-ARn are stored to the first storage column 310, and the first digital green signals DG11-DG1n corresponding to the first green signals AG11-AG1n It is stored to the second storage column 311. Thereafter, in the second storage period ST2 between the pulse wave P _G21 and the pulse wave P _R2 of the trigger signal FS, the register 31 converts the digital red signal DR1-DRn according to the pulse wave P1 of the read signal Vsync. A digital green signal DG11-DG1n output. In other words, in the second storage period ST2, the digital red signal DR1-DRn and the first digital green signal DG11-DG1n are read out from the register 31 in accordance with the pulse wave P1. In this embodiment, the digital red signal DR1-DRn and the first digital green signal DG11-DG1n are read out from the register 31 in a specific order, so that the output data format is "DR1, DG11, DR2, DG12, .... ..DRn, DG1n", and it corresponds to the sensing operation of the sensing period TD.

According to the above, in the second storage period ST2, the digital red signals DR1-DRn and the first green signals AG11-AG1n are read out from the register 31 in accordance with the pulse wave P1. Meanwhile, in the second storage period ST2, the detecting unit 12 sequentially outputs the second green signal AG21-AG2n and the blue signal AB1-ABn, and the corresponding second digital green signal DG21-DG2n is stored to the first storage column. 310, and the corresponding digital blue signals DB1-DBn are stored to the second storage column 311. Thereafter, in the third storage period ST3 between the pulse waves P _R and F _{G2 below the} trigger signal FS, the register 31 sets the second digital green signal DG21 based on the pulse wave P2 of the read signal Vsync. DG2n is output with the digital blue signal DB1-DBn. In other words, in the third storage period ST3, the second digit green signals DG21-DG2n and the digital blue signals DB1-DBn are read out from the register 31 in accordance with the pulse wave P2. In this embodiment, the second digit green signal DG21-DG2n and the digital blue signal DB1-DBn are read out from the register 31 in a specific order, so that the output data format is "DG21, DB1, DG22, DB2,... ... DG2n, DBn", and it corresponds to the sensing operation of the sensing period TD.

Therefore, according to the above manner, output data "DR1, DG11, DR2, DG12, ... DRn, DG1n" and "DG21, DB1, DG22, DB2, ... corresponding to each sensing period are generated. ...DG2n, DBn". The complex interleaved output data "DR1, DG11, DR2, DG12, ... DRn, DG1n" read from the scratchpad 31 by the sensing operation of the sensing unit 12 during the plurality of sensing periods. "DG21, DB1, DG22, DB2, ... DG2n, DBn" has a Bayer pattern data format.

In the embodiment of the present invention, the digital red signals DR1-DRn and the second digital green signals DG21-DG2n are stored in and read from the first storage column 310, and the first digital green signals DG11-DG1n and digits. The manner and sequence in which the blue signals DB1-DBn are stored and read from the second storage column 311 can be determined by the designer or system requirements. The digital red signal DR1-DRn and the first digital green signal DG11-DG1n read from the temporary memory 31 can have the data format "DR1, DG11, DR2, DG12, .." as long as it is in the second storage period ST2. ....DRn, DG1n", and enables the second digit green signal DG21-DG2n and the digital blue signal DB1-DBn read from the register 31 to have the data format "DG21" during the third storage period ST3, The writing and reading modes and sequences of DB1, DG22, DB2, ... DG2n, DBn" can be selectively applied to the register 31 of the present invention. For example, for the writing and reading of the digital red signal DR1-DRn and the first digital green signal DG11-DG1n, the digital red signals DR1-DRn are sequentially written to the first storage column 310, and the first digital green signal DG11- The DG1n is sequentially written to the second storage column 311. In addition, the first storage column 310 and the second storage column 311 are interleaved so that the read data format is "DR1, DG11, DR2, DG12, ... DRn, DG1n".

The embodiment of FIG. 2 is such that during each sensing period, the driving unit 13 drives the red light source RL once, then the green light source GL for the first time, the green light source GL for the second time, and finally the blue light source. BL is an example. In other embodiments, during each sensing period, the driving unit 13 may first drive the green light source GL, then drive the red light source RL once, then drive the green light source GL a second time, and finally drive the blue light source BL. Once, as shown in Figure 4. The sensing unit 12 outputs the first green signal AG11-AG1n to the analog-to-digital converter 30 of the readout unit 14 according to the pulse wave P _{G1 of the} trigger signal FS, and the red signal AR1 according to the pulse wave P _{R of the} trigger signal FS. The -ARn is output to the analog to digital converter 30 of the readout unit 14. Corresponding first digit green signals DG11-DG1n and digital red signals DR1-DRn are then read out from the register 31 in a specific order according to the pulse wave P1, so that the output data format is "DG11, DR1, DG12, DR2, .. ....DG1n, DRn,". Further, the sensing unit 12 outputs the second green signal AG21-AG2n to the analog-to-digital converter 30 of the readout unit 14 according to the pulse wave P _{G2 of the} trigger signal FS, and blue according to the pulse wave P _{B of the} trigger signal FS. The color signals AB1-ABn are output to the analog-to-digital converter 30 of the readout unit 14. The corresponding second digit green signal DG21-DG2n and the digital blue signal DB1-DBn are then read out from the register 31 in a specific order according to the pulse wave P2, so that the output data format is "DG21, DB1, DG22, DB2,. .....DG2n, DBn". The complex interleaved output data "DG11, DR1, DG12, DR2, ... DG1n, DRn," read from the scratchpad 31 by the sensing operation of the sensing unit 12 during the plurality of sensing periods. With "DG21, DB1, DG22, DB2, ... DG2n, DBn", there is a data format of Bell Chart.

In another embodiment, the driving unit 13 may first drive the green light source GL, then drive the red light source RL once, then drive the blue light source BL once, and finally drive the green light source GL a second time, as shown in FIG. Shown. The sensing unit 12 outputs the first green signal AG11-AG1n to the analog-to-digital converter 30 of the readout unit 14 according to the pulse wave P _{G1 of the} trigger signal FS, and the red signal AR1 according to the pulse wave P _{R of the} trigger signal FS. The -ARn is output to the analog to digital converter 30 of the readout unit 14. The corresponding first digit green signal DG11-DG1n and the digital red signal DR1-DRn are then read out from the register 31 in a specific order according to the pulse glass P1, so that the output data format is "DG11, DR1, DG12, DR2,,. .....DG1n,DRn,". In addition, the sensing unit 12 outputs the blue signal AB1-ABn to the analog-to-digital converter 30 of the readout unit 14 according to the pulse wave P _B of the trigger signal FS, and the second wave according to the pulse wave P _{G2 of the} trigger signal FS. The green signals AG21-AG2n are output to the analog-to-digital converter 30 of the readout unit 14. The corresponding digital blue signal DB1-DBn and the second digital green signal DG21-DG2n are then read out from the register 31 in a specific order according to the pulse wave P2, so that the output data format is "DB1, DG21, DB2, DG22,. .....DBn, DG2n". The complex interleaved output data "DG11, DR1, DG12, DR2, ... DG1n, DRn" read from the scratchpad 31 by the sensing operation of the sensing unit 12 during the plurality of sensing periods "DB1, DG21, DB2, DG22, ... DBn, DG2n" has the data format of the Bell Chart.

In the embodiment of FIG. 3, the reading unit 14 firstly transmits the red signal AR1-ARn, the first green signal AG11-AG1n, the second green signal AG21-AG2n, and the blue signal AB1- from the detecting unit 12. The ABn is converted into a digital format, and then stored in the corresponding first storage column 310 and the second storage column 311 in the temporary storage unit 31. In other embodiments, the read unit 14 first stores the red signal AR1-ARn, the first green signal AG11-AG1n, the second green signal AG21-AG2n, and the blue signal AB1-ABn from the detecting unit 12 into one. In the scratchpad, it is converted to a digital format after being read from the scratchpad. Referring to FIG. 6, the readout unit 14 includes a register 60 and an analog to digital converter 61. Like the register 31 of FIG. 3, the register 60 also includes a first storage column 610 and a second storage column 611. The red signal AR1-ARn, the first green signal AG11-AG1n, the second green signal AG21-AG2n, and the blue signal AB1-ABn from the detecting unit 12 are stored in the register 60, after which After being read from the register 60, it is converted into a digital format by the analog-to-digital converter 61.

In the embodiment of FIG. 6, the manner in which the signal is written to the register 60 and the signal is read from the register 60 is the same as in FIG. 2, except that the signal written to the register 60 is Analog signal. Therefore, the complex interleaved output data "AR1, AG11, AR2, AG12, ... ARn, AG1n read from the scratchpad 60 by the sensing operation of the sensing unit 12 during the plurality of sensing periods. "And" AG21, AB1, AG22, AB2, ... AG2n, ABn" have the data format of the Bell Chart. Thereafter, the complex interleaved output data "DR1, DG11, DR2, DG12, ... DRn, DG1n" and the output data "DG21, DB1, DG22" obtained after the analog-to-digital conversion are performed via the analog-to-digital converter 61. DB2, ... DG2n, DBn" also has a data format for Bell Chart.

The present invention has been disclosed in the above preferred embodiments, and is not intended to limit the scope of the present invention. Any one of ordinary skill in the art can make a few changes without departing from the spirit and scope of the invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

Figure 1:

1. . . Sensing device

10. . . Light guide

11. . . Cylindrical lens

12. . . Sensing unit

13. . . Drive unit

14. . . Readout unit

15. . . Target

120 ₁ -120 _N . . . Sensing cell

RL. . . Red light source

GL. . . Green light source

BL. . . Blue light source

AR1-ARn. . . Red signal

AG11-AG1n. . . First green signal

AG21-AG2n. . . Second green signal

AB1-ABn. . . Blue signal

SR, SG, SB. . . Drive signal

Figure 2:

LED_R. . . Red light source

LED_G1, LED_G2. . . Luminous state of green light source

LED_B. . . Blue light source

SIG. . . Signal transmission status from the sensing unit to the reading unit

TD1, TD2. . . Sensing period

FS. . . Trigger signal

P _R1 , P _G11 , P _G21 , P _B1 , P _R2 , P _G12 , P _G22 , P _B2 . . . Pulse wave of trigger signal

Vout_R. . . The period during which the red signal is output to the readout unit

Vout_G1. . . The period during which the first green signal is output to the readout unit

Vout_G2. . . The period during which the second green signal is output to the readout unit

Vout_B. . . The period during which the blue signal is output to the readout unit

Vsync. . . Readout signal

P1, P2. . . Read the pulse wave of the signal

ST1, ST2, ST3. . . Storage period

Figure 3:

30. . . Analog digital converter

31. . . Register

310. . . First storage column

311. . . Second storage column

DR1-DRn. . . Digital red signal

DG11-DG1n. . . First digit green signal

DG21-DG2n. . . Second digit green signal

DB1-DBn. . . Digital blue signal

Figure 6

60. . . Register

61. . . Analog digital converter

610. . . First storage column

611. . . Second storage column

Figure 1 shows a sensing device in accordance with an embodiment of the present invention;

2 is a timing chart showing light emission states, signal transmission states, and related signals of a three-color light source according to an embodiment of the present invention;

Figure 3 is a view showing an embodiment of the reading unit in the sensing device of Figure 1;

4 is a timing chart showing light emission states, signal transmission states, and related signals of a three-color light source according to another embodiment of the present invention;

Figure 5 is a diagram showing the light-emitting state, signal transmission state, and associated signal timing diagram of a three-color light source according to still another embodiment of the present invention;

Fig. 6 is a view showing another embodiment of the reading unit in the sensing device of Fig. 1.

LED_R. . . Red light source

LED_G1, LED_G2. . . Luminous state of green light source

LED_B. . . Blue light source

SIG. . . Signal transmission status from the sensing unit to the reading unit

TD1, TD2. . . Sensing period

FS. . . Trigger signal

P _R1 , P _G11 , P _G21 , P _B1 , P _R2 , P _G12 , P _G22 , P _B2 . . . Pulse wave of trigger signal

Vout_R. . . The period during which the red signal is output to the readout unit

Vout_G1. . . The period during which the first green signal is output to the readout unit

Vout_G2. . . The period during which the second green signal is output to the readout unit

Vout_B. . . The period during which the blue signal is output to the readout unit

Vsync. . . Readout signal

P1, P2. . . Read the pulse wave of the signal

ST1, ST2, ST3. . . Storage period

Claims (8)

A sensing device for operating during a plurality of consecutive sensing periods, comprising: a red light source; a green light source; a blue light source; and a driving unit for driving the red light source at different times The green light source and the blue light source respectively emit a red light, a green light, and a blue light to a target, wherein the driving unit drives the green light source during each of the sensing periods Two times, driving the red light source once and driving the blue light source once; a sensing unit for respectively generating a plurality of first green signals according to the light reflected by the target being irradiated with the green light twice a plurality of second green signals, generating a plurality of red signals according to the light that is reflected by the target light by the red light, and generating a plurality of blue signals according to the light that the target is irradiated with the blue light once; and the analogous digital a converter for converting the first green signal, the second green signal, the red signal, and the blue signal into a complex first digit green a signal, a plurality of second digit green signals, a plurality of digit red signals, and a plurality of digit blue signals; and a register having a first storage column and a second storage column; wherein, during a first storage period, the signal The first storage column stores the digital red signals, and the second storage column stores the first digital green signals; The first storage column stores the second digit green signals during a second storage period, and the second storage column stores the digit blue signals; wherein, during the second storage period, the digits are red The signal is read from the first storage column, and the first digit green signals are read from the second storage column; wherein, during a third storage period, the second digit green signals are read from the first storage column And the digital blue signals are read from the second storage column; and wherein the digital red signals and the first digital green signals read from the temporary storage during the second storage period are The digital blue signal and the second digital green signal read from the register during the third storage period have a Bayer Pattern data format. The sensing device of claim 1, wherein, in each of the sensing periods, the driving unit sequentially drives the red light source once, drives the green light source twice, and drives the blue The color light source is once. The sensing device of claim 1, wherein, in each of the sensing periods, the driving unit sequentially drives the green light source for the first time, and drives the red light source once and second times. The green light source is driven and the blue light source is driven once. The sensing device of claim 1, wherein, in each of the sensing periods, the driving unit sequentially drives the green light source for the first time, drives the red light source once, and drives the blue The color illumination source is driven once and the green illumination source is driven a second time. A sensing device for operating during a plurality of consecutive sensing periods, comprising: a red light source; a green light source; a blue light source; and a driving unit for driving the red light source, the green light source, and the blue light source to emit a red light, respectively Green light, and a blue light to a target, wherein, in each of the sensing periods, the driving unit drives the green light source twice, drives the red light source once, and drives the blue light source once; a sensing unit configured to respectively generate a plurality of first green signals and a plurality of second green signals according to the light reflected by the target being irradiated with the green light twice, and the red light is reflected according to the target Light generating a plurality of red signals, generating a plurality of blue signals according to the light that the target is illuminated by the blue light; a register having a first storage column and a second storage column; and an analogous digit a converter coupled to the register; wherein, during a first storage period, the first storage column stores the red signals, and the second storage column stores the first green signals Wherein, during a second storage period, the first storage column stores the second green signals, and the second storage column stores the blue signals; wherein, during the second storage, the red signals are from The first storage column is read out, and the first green signals are read from the second storage column; wherein, during a third storage period, the second green signals are read from the first storage column, and the Waiting for a blue signal to be read from the second storage column; wherein the analog digital converter will read the red from the register a color signal, the first green signal, the second green signal, and the blue signal are converted to a digital type; and wherein the second storage period is read from the register and has a digital pattern The red signals and the first green signals and the blue signals read from the register during the third storage period and having a digital pattern and the second green signals have a Bell diagram (Bayer Pattern) ) data format. The sensing device of claim 5, wherein, in each of the sensing periods, the driving unit sequentially drives the red light source once, drives the green light source twice, and drives the blue The color light source is once. The sensing device of claim 5, wherein, in each of the sensing periods, the driving unit sequentially drives the green light source for the first time, and drives the red light source once and second times. The green light source is driven and the blue light source is driven once. The sensing device of claim 5, wherein, in each of the sensing periods, the driving unit sequentially drives the green light source for a first time, drives the red light source once, and drives the blue The color illumination source is driven once and the green illumination source is driven a second time.