TWI819631B - Image sensing device - Google Patents

Abstract

An image sensing device includes a first sensing circuit, a second sensing circuit, a reading circuit and an image processing circuit. The first sensing circuit is configured to perform light sensing to obtain a first image signal at a first stage. The second sensing circuit is configured to perform light sensing to obtain a second image signal at a second stage. An exposure time of the first stage is more than the exposure time of the second stage. The reading circuit is coupled to the first sensing circuit and the second sensing circuit. The reading circuit is configured to read out the first image signal in a sub-stage of the first stage. The reading circuit is configured to read out the second image signal in a sub-stage of the second stage. The image processing circuit is coupled to the reading circuit, and is configured to a third image signal according to the first image signal and the second image signal

Description

Image sensing device

This case involves a sensing device. Specifically, this case involves an image sensing device.

The brightness sensed by the PIN diode in the existing light sensor is above 7 lux. PIN type diodes are characterized by high sensing sensitivity. However, under low-brightness light sources, the photocurrent generated by PIN-type diode sensing is small, making it difficult to read dark-state imaging.

Therefore, the above technology still has many shortcomings, and practitioners in the field need to develop other suitable circuit designs.

One aspect of this case involves an image sensing device. The image sensing device includes a first sensing circuit, a second sensing circuit, a reading circuit and an image processing circuit. The first sensing circuit is used for light sensing in the first stage to obtain the first image signal. The second sensing circuit is used for light sensing in the second stage to obtain the second image signal. The exposure time of the first stage is longer than the exposure time of the second stage. The reading circuit is coupled to the first sensing circuit and the second sensing circuit. The reading circuit is used to read the first image signal in a sub-stage of the first stage, and is used to read the second image signal in a sub-stage of the second stage. The image processing circuit is coupled to the reading circuit and used to generate a third image signal based on the first image signal and the second image signal.

Another aspect of this case involves an image sensing device. The image sensing device includes a first sensor, a second sensor and an image processing circuit. The first sensor is used for light sensing to obtain a first image signal. The second sensor is used for light sensing to obtain a second image signal. The image processing circuit is coupled to the first sensor and the second sensor, and is used to simultaneously read the first image signal and the second image signal to generate a third image signal.

The following will clearly illustrate the spirit of this application with drawings and detailed descriptions. Anyone with ordinary knowledge in the technical field, after understanding the embodiments of this application, can make changes and modifications based on the techniques taught in this application without departing from the spirit of this application. Spirit and scope.

The terms used herein are only used to describe specific embodiments and are not intended to be limiting. Singular forms such as "a", "this", "this", "this" and "the", as used herein, also include the plural forms.

The words "includes", "includes", "has", "contains", etc. used in this article are all open terms, which mean including but not limited to.

Regarding the terms used in this article, unless otherwise noted, they generally have the ordinary meanings of each term used in this field, the content of this case, and the special content. Certain terms used to describe the present invention are discussed below or elsewhere in this specification to provide those skilled in the art with additional guidance in describing the present invention.

In some embodiments, in order to make the operation of the image sensing device 100 in this case easy to understand, please refer to Figure 1 and Figure 2 together. The image sensing device 100 includes a first sensing circuit 110 and a second sensing circuit 120 , reading circuit 130 and image processing circuit 140.

In some embodiments, the first sensing circuit 110 is used to perform light sensing in the first stage I1 to obtain the first image signal Vo1. The second sensing circuit 120 is used for light sensing in the second stage I2 to obtain the second image signal Vo2. The first exposure time of the first stage I1 (for example: the first sub-stage I11) is greater than the second exposure time of the second stage I2 (for example: the third sub-stage I21). The reading circuit 130 is coupled to the first sensing circuit 110 and the second sensing circuit 120 .

Then, the reading circuit 130 is used to read the first image signal Vo1 in a sub-stage of the first stage I1 (for example: the second sub-stage I12), and is used to read the first image signal Vo1 in a sub-stage of the second stage I2 (for example: the fourth sub-stage I22 ) reads the second image signal Vo2. The image processing circuit 140 is coupled to the reading circuit 130 and used to generate a third image signal according to the first image signal Vo1 and the second image signal Vo2. It should be noted that the first sub-stage I11 of the first stage I1 and the third sub-stage I13 of the second stage I2 are sensing stages (or exposure stages). The second sub-phase I12 of the first phase I1 and the fourth sub-phase I22 of the second phase I2 are read phases.

In some embodiments, please refer to Figures 1 and 2, the image sensing device 100 further includes a data line D1, a first gate line transmitting the first gate signal G1, and a third gate line transmitting the second gate signal G2. Two gate lines, a first common signal line transmitting the first common signal COM1 and a second common signal line transmitting the second common signal COM2.

In some embodiments, the data line D1 is coupled to the first sensing circuit 110 , the second sensing circuit 120 and the reading circuit 130 , and is used to transmit the first image signal Vo1 and the second image signal Vo2 to the reading circuit 130 .

In some embodiments, the first gate line transmitting the first gate signal G1 and the first common signal line transmitting the first common signal COM1 are coupled to the first sensing circuit 110 .

In some embodiments, the second gate line transmitting the second gate signal G2 and the second common signal line transmitting the second common signal COM2 are coupled to the second sensing circuit 120 .

In some embodiments, the first sensing device 110 includes a photosensitive diode PIN1, a first capacitor Cdiode and a first reading transistor R1.

In some embodiments, please refer to Figures 1 and 2, the photodiode PIN1 is used for light sensing in the first stage I1 to generate the first image signal Vo1. The first capacitor Cdiode is coupled to the photosensitive diode PIN1 and used to store the first image signal Vo1. The first reading transistor R1 is coupled to the photosensitive diode PIN1 and the first capacitor Cdiode, and is used to read the first image signal to the data line D1.

In some embodiments, the photosensitive diode PIN1 may be a PIN-type diode (or phase-shifted switching diode). In some embodiments, the sensing time (or exposure time) of the photodiode PIN1 is generally 10 ms. The brightness sensed by the photodiode PIN1 is above 7 lux. The photodiode PIN1 is characterized by high sensing sensitivity. However, under a low-brightness light source, the photocurrent generated by the photosensitive diode PIN1 is small, making it difficult to read dark-state imaging.

It should be noted that the photosensitive diode PIN1 can read dark-state imaging, but the sensing time (or exposure time) of the photosensitive diode PIN1 needs to be extended to 1 second (s) to read low-brightness images. Dark state imaging.

In some embodiments, please refer to FIGS. 1 and 2 , the second sensing circuit 120 includes a phototransistor T1 , a second capacitor Cst and a second reading transistor R2 . The photosensitive transistor T1 is used for light sensing in the second stage I2 to generate the second image signal Vo2. The second capacitor Cst is coupled to the photosensitive transistor T1 and used to store the second image signal Vo2. The second reading transistor R2 is coupled to the photosensitive transistor T1 and the second capacitor Cst, and is used to read the second image signal Vo2 to the data line D1.

In some embodiments, please refer to FIGS. 1 and 2 , the photosensitive transistor T1 may be a gap type thin film transistor (Gap type TFT). In some embodiments, the sensing time (or exposure time) of the photosensitive transistor T1 is usually within 10 ms. The brightness sensed by the photosensitive transistor T1 can be below 7 lux. The photosensitive transistor T1 is characterized by a high photocurrent value sensed and a small structural area of the photosensitive transistor T1. Under a low-brightness light source, the sensing time (or exposure time) of the photosensitive transistor T1 can be compared to the sensing time (or exposure time) of a PIN diode (or phase-shift switching diode) short.

It should be noted that the first image signal Vo1 obtained by the photosensitive diode PIN1 is a low-exposure image. The second image signal Vo2 obtained by the photosensitive transistor T1 is a high-exposure image.

In some embodiments, read circuit 130 may be an integrating circuit. The reading circuit 130 reads the first image signal Vo1 and the second image signal Vo2 according to the control signal CLR and the reference voltage Vref, and then performs waveform conversion or product integration on the first image signal Vo1 and the second image signal Vo2. points compensation.

In some embodiments, the image processing circuit 140 uses high dynamic range imaging technology (High Dynamic Range Imaging, HDR) to superimpose the first image signal Vo1 and the second image signal Vo2 with different image exposures into a third image with higher contrast. signal (not shown in the picture).

Figure 3 is a schematic structural diagram of the image sensing device 100 according to some embodiments of the present invention. In some embodiments, please refer to Figure 3, because this case integrates the photosensitive diode PIN1 and the photosensitive transistor T1 on one sensing pixel to perform image sensing (or exposure). Therefore, the photosensitive transistor T1 needs to be coupled to the second capacitor Cst, which results in compressed space for the photosensitive diode PIN1 in structural design. R1 corresponds to the first reading transistor of the first sensing circuit 110 of the image sensing device 100 . R2 corresponds to the second reading transistor of the second sensing circuit 120 of the image sensing device 100 . M1, M2 and M3 are different metal layers respectively. B is the glass substrate of the image sensing device 100 .

Figure 4 is a circuit block diagram of the image sensing device 100A according to some embodiments of the present invention. Figure 5 is a signal timing diagram of the image sensing device 100A according to some embodiments of the present invention. In some embodiments, the difference between the image sensing device 100 in Figure 1 and the image sensing device 100A in Figure 4 is that the first sensing circuit 110A and the second sensing circuit 120A share a capacitor Cdiode2.

The image sensing device 100A includes a first sensing circuit 110A, a second sensing circuit 120A, a reading circuit 130A, and an image processing circuit 140A.

In some embodiments, the first sensing circuit 110A is used to perform light sensing in the first stage I1 to obtain the first image signal Vo1. The second sensing circuit 120A is used for light sensing in the second stage I2 to obtain the second image signal Vo2. The exposure time of the first stage I1 (for example: the first sub-stage I11) is greater than the exposure time of the second stage I2 (for example: the third sub-stage I21). The reading circuit 130A is coupled to the first sensing circuit 110A and the second sensing circuit 120A.

Then, the reading circuit 130A is used to read the first image signal Vo1 in a sub-stage of the first stage I1 (for example, the second sub-stage I12), and is used to read the first image signal Vo1 in a sub-stage of the second stage I2 (for example, the fourth sub-stage I22 ) reads the second image signal Vo2. The image processing circuit 140A is coupled to the reading circuit 130 and used to generate a third image signal according to the first image signal Vo1 and the second image signal Vo2.

In some embodiments, please refer to Figures 4 and 5. The image sensing device 100A further includes a data line D1, a first gate line transmitting the first gate signal G1, and a third gate line transmitting the second gate signal G2. Two gate lines, a first common signal line transmitting the first common signal COM1, a second common signal line transmitting the second common signal COM2 and the capacitor Cdiode2. The data line D1 is coupled to the first sensing circuit 110A and the reading circuit 130A. The second sensing circuit 120A is coupled to the data line D1 through the first sensing circuit 110A and the capacitor Cdiode2.

In some embodiments, the first gate line transmitting the first gate signal G1 and the first common signal line transmitting the first common signal COM1 are coupled to the first sensing circuit 110A.

In some embodiments, the second gate line transmitting the second gate signal G2 and the second common signal line transmitting the second common signal COM2 are coupled to the second sensing circuit 120A. It should be noted that the second gate line transmitting the second gate signal G2 does not intersect with the first gate line transmitting the first gate signal G1.

In some embodiments, the first sensing circuit 110A includes a photodiode PIN1 and a first read transistor R1. The photodiode PIN1 is used for light sensing in the first stage I1 to generate the first image signal Vo1, which is stored in the capacitor Cdiode2. The first reading transistor R1 is coupled to the photosensitive diode PIN1 and the capacitor Cdiode2, and is used to read the first image signal Vo1 to the data line D1.

In some embodiments, please refer to FIGS. 4 and 5 , the second sensing circuit 120A includes a photosensitive transistor T1 and a second reading transistor R2. The photosensitive transistor T1 is used for light sensing in the second stage I2 to generate the second image signal Vo2. The second reading transistor R2 is coupled to the photosensitive transistor T1 and the capacitor Cdiode2, and is used to read the second image signal Vo2 and transmit it to the data line D1 through the first reading transistor R1.

It should be noted that in the third sub-phase I21 of the second phase I2, the photocurrent generated by the photosensitive transistor T1 is greater than the photocurrent generated by the photodiode PIN1. In some embodiments, the photocurrent generated by the phototransistor T1 is approximately one thousand times the photocurrent generated by the photodiode PIN1. Therefore, the photocurrent generated by the photosensitive transistor T1 is not affected by the photocurrent generated by the photodiode PIN1.

In some embodiments, read circuit 130A may be an integrating circuit. The reading circuit 130A uses the control signal CLR and the reference voltage Vref to After reading the first image signal Vo1 and the second image signal Vo2, waveform conversion or integral compensation is performed on the first image signal Vo1 and the second image signal Vo2.

In some embodiments, the image processing circuit 140A uses high dynamic range imaging technology (High Dynamic Range Imaging, HDR) to superimpose the first image signal Vo1 and the second image signal Vo2 with different image exposures into a third image with higher contrast. signal (not shown in the picture).

In some embodiments, the time of the third sub-phase I21 of the second phase I2 of FIG. 5 is longer than the time of the third sub-phase I21 of the second phase I2 of FIG. 2 .

Figure 6 is a schematic structural diagram of an image sensing device 100A according to some embodiments of the present invention. In some embodiments, please refer to Figure 6, because this case integrates the photosensitive diode PIN1 and the photosensitive transistor T1 on one sensing pixel to perform image sensing (or exposure). Therefore, compared with the embodiment of FIG. 3 , the image sensing device 100A of FIG. 6 lacks the second capacitor Cst of the image sensing device 100 of FIG. 3 . Therefore, the image sensing device 100A has some extra space in the sensing pixels for other circuit planning. R1 corresponds to the first reading transistor of the first sensing circuit 110A of the image sensing device 100A. R2 corresponds to the second reading transistor of the second sensing circuit 120A of the image sensing device 100A. M1, M2 and M3 are different metal layers respectively. B is the glass substrate of the image sensing device 100 .

Figure 7 is a circuit block diagram of the image sensing device 200 according to some embodiments of the present invention. Figure 8 is a signal timing diagram of the image sensing device 200 according to some embodiments of the present invention.

In some embodiments, please refer to FIGS. 7 and 8 , the image sensing device 200 includes a first sensor 210 , a second sensor 220 and an image processing circuit 230 . The first sensor 210 is used for light sensing to obtain the first image signal Vo1. The second sensor 220 is used for light sensing to obtain the second image signal Vo2. The image processing circuit 230 is coupled to the first sensor 210 and the second sensor 220 and is used to simultaneously read the first image signal Vo1 and the second image signal Vo2 to generate a third image signal.

In some embodiments, please refer to FIGS. 7 and 8 , the first sensor 210 includes a first sensing circuit 211 and a first reading circuit 212 .

In some embodiments, the first sensing circuit 211 includes a first data line D1, a photodiode PIN1 and a first reading transistor R1. The first data line D1 is used to transmit the first image signal Vo1 to the image processing circuit 230 . The photodiode PIN1 is used for light sensing to generate the first image signal Vo1. The first reading transistor R1 is coupled to the first data line D1 and the photosensitive diode PIN1, and is used to read the first image signal Vo1.

In some embodiments, please refer to FIGS. 7 and 8 , the second sensor 220 includes a second sensing circuit 221 and a second reading circuit 222 . In some embodiments, the second sensing circuit 221 includes a second data line D2, a photosensitive transistor T1 and a second reading transistor R2. The second data line D2 is used to transmit the second image signal Vo2 to the image processing circuit 230 . The photosensitive transistor T1 is used for light sensing to generate the second image signal Vo2. The second reading transistor R2 is coupled to the second data line D2 and the photosensitive transistor T1, and is used to read the second image signal Vo2.

In some embodiments, the first reading circuit 212 is coupled to the image processing circuit 230 and used to read the first image signal Vo1 of the first sensing circuit 211 .

In some embodiments, the second reading circuit 222 is coupled to the image processing circuit 230 and used to read the second image signal Vo2 of the second sensing circuit 221 .

In some embodiments, the first reading circuit 212 may be an integrating circuit. The reading circuit 212 reads the first image signal Vo1 according to the control signal CLR1 and the reference voltage Vref, and then performs waveform conversion or integral compensation on the first image signal Vo1. Meanwhile, the second reading circuit 222 may be an integrating circuit. The reading circuit 222 reads the second image signal Vo2 according to the control signal CLR2 and the reference voltage Vref, and then performs waveform conversion or integral compensation on the second image signal Vo2.

In some embodiments, the image processing circuit 230 uses high dynamic range imaging technology (High Dynamic Range Imaging, HDR) to superimpose the first image signal Vo1 and the second image signal Vo2 with different image exposures into a third image with higher contrast. signal (not shown in the picture).

It should be noted that the embodiment in Figure 1 and the embodiment in Figure 4 perform exposure and reading in stages. The embodiment in Figure 7 performs exposure and reading at the same time. The first sensor 210 and the second sensor 220 operate independently of each other and do not affect each other.

According to the aforementioned embodiments, the present invention provides an image sensing device (for example: the image sensing device 100 in Figure 1, the image sensing device 100A in Figure 4, and the image sensing device 200 in Figure 7) to obtain different images. exposed Photometric image signals are used to obtain higher contrast images.

Although this case is disclosed above with detailed embodiments, this case does not exclude other feasible implementation forms. Therefore, the scope of protection in this case shall be determined by the scope of the appended patent application and shall not be limited by the foregoing embodiments.

For those skilled in the art, various modifications and modifications can be made to the present application without departing from the spirit and scope of the present application. Based on the foregoing embodiments, all changes and modifications made to this case are also covered by the protection scope of this case.

100~100A, 200: Image sensing device

110~110A: first sensing circuit

120~120A: Second sensing circuit

130~130A: Reading circuit

140~130A: Image processing circuit

R1~R2: read transistor

PIN1: Photosensitive diode

Cdiode: the first capacitor

Cst: second capacitor

D1~D2: data line

T1: Photosensitive transistor

VGG, CLR, CLR1, CLR2: control signal

Vx, Vz: potential

COM1~COM2: common signals

G1~G2: Gate signal

Vout, Vout1, Vout2: output signal

Vref: reference voltage

I1~I2: stage

I11~I12, I21~I22: sub-stages

Vo1, Vo2: video signal

M1~M3: metal layer

B:Substrate

Cdiode2: capacitor

210: First sensor

220: Second sensor

211: First sensing circuit

221: Second sensing circuit

212,222:Reading circuit

230:Image processing circuit

The contents of this case can be better understood with reference to the implementation methods in the following paragraphs and the following diagrams: Figure 1 is a schematic circuit block diagram of an image sensing device according to some embodiments of the present invention; Figure 2 is a schematic diagram of signal timing of an image sensing device according to some embodiments of this case; Figure 3 is a schematic structural diagram of an image sensing device according to some embodiments of this case; Figure 4 is a schematic circuit block diagram of an image sensing device according to some embodiments of this case; Figure 5 is a signal timing diagram of an image sensing device according to some embodiments of this case; Figure 6 is a schematic structural diagram of an image sensing device according to some embodiments of this case; Figure 7 is a circuit block diagram of an image sensing device according to some embodiments of this case; and Figure 8 is a signal timing diagram of an image sensing device according to some embodiments of the present invention.

Domestic storage information (please note in order of storage institution, date and number) without Overseas storage information (please note in order of storage country, institution, date, and number) without

100:Image sensing device

110: First sensing circuit

120: Second sensing circuit

130:Reading circuit

140:Image processing circuit

R1~R2: read transistor

PIN1: Photosensitive diode

Cdiode: the first capacitor

Cst: second capacitor

D1: data line

T1: Photosensitive transistor

VGG, CLR: control signal

Vx, Vz: potential

COM1~COM2: common signals

G1~G2: gate signal

Vout: output signal

Vref: reference voltage

Claims (10)

An image sensing device, including: a first sensing circuit for performing light sensing in a first stage to obtain a first image signal; a second sensing circuit for performing light sensing in a second stage Light sensing to obtain a second image signal, wherein a first exposure time of the first stage is greater than a second exposure time of the second stage; and a reading circuit coupled to the first sensing circuit and the second sensing circuit, and is used to read the first image signal in a first sub-stage of the first stage, and is used to read the second image signal in a second sub-stage of the second stage. ; and an image processing circuit coupled to the reading circuit and used to generate a third image signal based on the first image signal and the second image signal. The image sensing device of claim 1, wherein the image sensing device further includes a data line, the data line is coupled to the first sensing circuit, the second sensing circuit and the reading circuit, and uses To transmit the first image signal and the second image signal to the reading circuit, wherein the first sensing circuit includes: a photosensitive diode for performing light sensing in the first stage to generate the third an image signal; a first capacitor coupled to the photosensitive diode and used to store the first image signal; and a first reading transistor coupled to the photosensitive diode and the first capacitor content, and is used to read the first image signal transmitted to the data line. The image sensing device of claim 2, wherein the second sensing circuit includes: a photosensitive transistor for performing light sensing in the second stage to generate the second image signal; a second capacitor , coupled to the photosensitive transistor, and used to store the second image signal; and a second reading transistor, coupled to the photosensitive transistor and the second capacitor, and used to read the data transmitted to the data line. the second image signal. The image sensing device as claimed in claim 1, wherein the image sensing device further includes a data line and a capacitor, the data line is coupled to the first sensing circuit and the reading circuit, and the second sensing The circuit is coupled to the data line through the first sensing circuit and the capacitor, wherein the first sensing circuit includes: a photosensitive diode for performing light sensing in the first stage to generate the first an image signal is stored in the capacitor; and a first reading transistor is coupled to the photodiode and the capacitor and is used to read the first image signal transmitted to the data line. The image sensing device as claimed in claim 4, wherein the second sensing circuit includes: a photosensitive transistor for performing light sensing in the second stage to produce generate the second image signal; and a second reading transistor, coupled to the photosensitive transistor and the capacitor, and used to read the second image signal, and transmit it to the first reading transistor data line. An image sensing device, including: a first sensor for performing light sensing to obtain a first image signal, wherein the first sensor includes: a photodiode for performing Light sensing to generate the first image signal; a second sensor for light sensing to obtain a second image signal, wherein the second sensor includes: a photosensitive transistor for for performing light sensing to generate the second image signal; and an image processing circuit coupled to the first sensor and the second sensor, and for simultaneously reading the first image signal and the second image signal. The second image signal is used to generate a third image signal. The image sensing device of claim 6, wherein the first sensor includes a first sensing circuit, wherein the first sensing circuit includes: a first data line for transmitting the first image signal to The image processing circuit; and a first reading transistor, coupled to the first data line and the photosensitive diode, and used to read the first image signal. The image sensing device according to claim 7, wherein the first sensing circuit further includes: a first reading circuit coupled to the image processing circuit and used to read the first sensing circuit image signal. The image sensing device of claim 8, wherein the second sensor includes a second sensing circuit, wherein the second sensing circuit includes: a second data line for transmitting the second image signal to The image processing circuit; and a second reading transistor, coupled to the second data line and the photosensitive transistor, and used to read the second image signal. The image sensing device as claimed in claim 9, wherein the second sensing circuit further includes: a second reading circuit coupled to the image processing circuit and used to read the second portion of the second sensing circuit. image signal.