CN105824185A - X-ray sensing panel - Google Patents

Abstract

The invention provides an X-ray sensing panel, which comprises multiple data lines, multiple scanning lines, multiple pixel elements, multiple integrator circuits and multiple compensation circuits, wherein the multiple pixel elements are configured into a matrix array; the multiple pixel elements are coupled to corresponding data lines and the scanning lines to generate a sensing signal; the integrator circuit comprises an operational amplifier, and an anti-phase input terminal of the operational amplifier is coupled to the corresponding data line to receive the sensing signal via the data line; and the multiple compensation circuits are coupled to a non anti-phase input terminal of the corresponding operational amplifier for providing a compensation signal to a corresponding integrator circuit.

Description

X-ray sensing panel

Technical field

The invention relates to a kind of X-ray sensing panel, in particular to a kind of X-ray sensing panel that can eliminate noise.

Background technology

Traditional X-ray armarium uses egative film formula as interpretation and storage.In order to provide more preferable image quality and storing mode, digitized X-ray armarium can be used.The most digitized X-ray armarium uses X-ray sensing panel to sense X-ray.But, the process of analog signal digital, can produce along with many noises, sensor and the reading IC of such as X-ray sensing face intralaminar part also can produce noise, can impact interpretation.In order to provide armarium more accurately, it is necessary to provide a kind of X-ray panel eliminating noise.

Summary of the invention

The invention relates to a kind of X-ray sensing panel, circuit for eliminating noise can be compensated by one, to reach X-ray sensing result more accurately.

According to one embodiment of the invention, a kind of X-ray sensing panel is proposed.X-ray sensing panel comprises a plurality of data lines, multi-strip scanning line, multiple pixel element, multiple integrator circuit and multiple compensation circuit.Multiple pixel elements are configured to a matrix array, and these pixel elements are coupled to corresponding data wire and scan line, in order to produce a sensing signal.These integrator circuits comprise an operational amplifier, and an inverting input of operational amplifier is coupled to corresponding data wire, in order to receive sensing signal through thus data wire.These compensate circuit and are coupled to a non-inverting input of corresponding operational amplifier, in order to provide a compensation signal to corresponding integrator circuit.

Accompanying drawing explanation

For the above-mentioned purpose of the present invention, feature and advantage can be become apparent, below in conjunction with accompanying drawing, the detailed description of the invention of the present invention is elaborated, wherein:

Fig. 1 illustrates the block chart of the X-ray sensing panel 100 of an embodiment.

Fig. 2 illustrates the circuit diagram of the X-ray sensor architecture in the X-ray sensing panel 100 of an embodiment.

Fig. 3 illustrates the equivalent circuit diagram of the transistor TFT of an embodiment.

Fig. 4 illustrates the sequential chart compensating circuit of an embodiment.

In figure, element numbers is as follows:

100:X photo sensing panel

110: matrix array

120: scan drive circuit

130₁～130_m: compensate circuit

I₁～I_m: integrator circuit

D₁～D_m: data wire

G₁～G_n: scan line

P (x, y): pixel element

140: scintillator

TFT: transistor

S_D、S_E、S_comp、S_O: signal

PD: photodiode

Op: operational amplifier

Vbias、Vd、Vg、Vgh、Vgh、Vgl、V_TFTOut, V+, V-, Δ V1, Δ V2: voltage

C1: electric capacity

Vref: alternating-current voltage source

S1: switch

t_r: during rising

t_f: during decline

Detailed description of the invention

Refer to the block chart that Fig. 1, Fig. 1 illustrate the X-ray sensing panel 100 of an embodiment.X-ray sensing panel 100 comprises a plurality of data lines D1-Dm, multi-strip scanning line G₁～G_n, multiple pixel element P (x, y), multiple integrator circuit I₁～I_mAnd multiple compensation circuit 130₁～130_m.(x, y) is configured to a matrix array 110 to multiple pixel element P, and (x y) is coupled to corresponding data wire D to pixel element P_xAnd scan line G_y.In this embodiment, (x, y) in order to produce a sensing signal S for pixel element P_E.Integrator circuit 130x comprises an operational amplifier Op (being illustrated in Fig. 2), and an inverting input (V-) of operational amplifier Op is coupled to corresponding data wire D_x, in order to receive sensing signal S via data wire Dx_E.Compensate circuit 130x and be coupled to a non-inverting input (V+) of corresponding operational amplifier Op, in order to provide a compensation signal S_compTo corresponding integrator circuit Ix.X-ray sensing panel 100 also can comprise scan driving circuit 120, in order to via scan line G₁～G_nScanning signal S is provided_GTo those pixel elements.

Fig. 2 illustrates the circuit diagram of the X-ray sensor architecture in the X-ray sensing panel 100 of an embodiment.In this embodiment, x optical signal is converted to visible light signal S by a scintillator (Scintillator) 140 by X-ray sensing panel 100_O.And these pixel elements all comprise an a photodiode PD and transistor TFT.Photodiode PD receives visible light signal S_O, and be converted to the sensing signal S of a signal of telecommunication_E, this sensing signal S_EValue this region corresponding connect the light intensity of received X-ray.Transistor TFT has one first end, one second end and one and controls end.First end of transistor TFT is coupled to second end of photodiode PD, transistor TFT and is coupled to an inverting input (V-) of integrator circuit.The control end of transistor TFT is in order to receive scanning signal S_G, and turn on according to the scanning signal of a high potential with by sensing signal S_EIt is sent to integrator circuit 130.Integrator circuit 130_xCan read data line line (such as D_x) the sensing signal S of pixel element_E.Scan drive circuit 120 transmits scan signal S_GTo string scan line (such as G_y) so that all of integrator circuit 130₁～130_mReceive the sensing signal S of all pixel elements of these row respectively_E.Integrator circuit converts electrical signals to digital signal after receiving sensing signal, does follow-up data for other circuit and processes, such as, produces x light image or transparency etc..

But, as scanning signal S_GWhen controlling transistor TFT on and off, the parasitic capacitance of transistor can produce noise, and the error of sensing signal can be caused to affect follow-up interpretation.Therefore, in this embodiment, one circuit 130 is compensated_XIt is coupled to integrator circuit I_XThe non-inverting input (V+) of operational amplifier Op, in order to provide a compensation signal S_compTo integrator circuit I_X.In one embodiment, compensate circuit and comprise an electric capacity C1, an alternating-current voltage source Vref and a switch S1.Electric capacity C1 is coupled to the non-inverting input (V+) of operational amplifier Op.Alternating-current voltage source Vref is coupled to C1 electric capacity.Switch S1 is coupled between non-inverting input (V+) and the alternating-current voltage source Vref of operational amplifier Op.But, but the present invention is not limited, and compensating circuit can implement with other circuit structures.

Refer to Fig. 3 and Fig. 4 embodiment compensating circuit with the explanation present invention.Fig. 3 illustrates the equivalent circuit diagram of the transistor TFT of an embodiment.The control end of transistor TFT, in order to receive scanning signal, has a voltage Vg.First end of transistor TFT, is defined herein as drain electrode end, is coupled to photodiode PD, has a voltage Vpd.Second end of transistor TFT, is defined herein as source terminal, is coupled to an inverting input (V-) of integrator circuit, has a voltage Vd.Photodiode PD receives a voltage Vbias, and has parasitic capacitance Cpd.Between control end and first end (drain electrode end) of transistor TFT, there is parasitic capacitance Cgs.Between control end and second end (source terminal) of transistor TFT, there is parasitic capacitance Cgd.Period when transistor TFT on and off, these parasitic capacitances can produce an error voltage in the output of transistor TFT, the electric charge that this error voltage can cause integrator circuit to read is different from the electric charge that photodiode produces, and then affect the accuracy of X-ray sensing value, the judged result of image can be affected.

Fig. 4 illustrates the sequential chart compensating circuit of an embodiment.At scanning signal S_GA rising period t of a high potential Vgh is changed over by an electronegative potential Vgl_r, due to the impact of the parasitic capacitance of transistor TFT, the output V of transistor TFT_TFTOutError voltage+Δ the V1 of a forward can be produced.Similar, at scanning signal S_GA decline period t of an electronegative potential Vgl is changed over by a high potential Vgh_f, due to the impact of the parasitic capacitance of transistor TFT, the output V of transistor TFT_TFTOutError voltage-Δ the V2 of a negative sense can be produced.

Therefore, in order to eliminate this error voltage, at scanning signal S_GBy an electronegative potential Vgl change over a high potential Vgh one rising period t_r, compensate the switch S1 conducting of circuit, in order to provide the compensation signal-Δ V1 with the opposite polarity negative voltage of error voltage+Δ V1.Similar, at scanning signal S_GA decline period t of an electronegative potential Vgl is changed over by a high potential Vgh_f, compensate the switch S1 conducting of circuit, in order to provide the compensation signal+Δ V2 with the opposite polarity forward voltage of error voltage-Δ V2.

Wherein error voltage Δ V1 and Δ V2 is determined by following equation:

$\mathrm{\ΔV}1=\mathrm{Vgh}\×\frac{\mathrm{Cgd}}{\mathrm{Cgd}+\mathrm{Cgd}}+\mathrm{Vbias}\×\frac{\mathrm{Cpd}}{\mathrm{Cgd}+\mathrm{Cpd}}$

$\mathrm{\ΔV}2=\mathrm{Vgl}\×\frac{\mathrm{Cgd}}{\mathrm{Cgd}+\mathrm{Cgd}}+\mathrm{Vbias}\×\frac{\mathrm{Cpd}}{\mathrm{Cgd}+\mathrm{Cpd}}$

As in figure 2 it is shown, compensate circuit to comprise an electric capacity C1, an alternating-current voltage source Vref and a switch S1.By during the rising changed at scanning signal potential or one decline during, switch S1 conducting, compensate circuit and the voltage of opposite polarity be provided because Q=C1*Vref=C1* Δ V=Cpd*Vpd, and can the contrary electric charge of polarization to offset Δ V1 and Δ V2.

It addition, a rising period t of the current potential change at scanning signal_rPeriod t is declined with one_fOutside period, switch S1 close, compensate circuit one Dc bias V is provided_offsetThe signal that compensates make up for voltage (offsetvoltage) as operational amplifier.Wherein, the capacitance of electric capacity C1 and the magnitude of voltage of alternating-current voltage source Vref can adjust according to reality application.Such as can preset applicable capacitance and magnitude of voltage for different crystal pipe.

Above-described embodiment provides a kind of X-ray sensing panel, compensates circuit by one and is couple to the non-inverting input of integrator circuit, in order to provide a compensation signal to integrator circuit.So, can be during the rising of scanning signal or during decline, it is provided that one compensates the error caused during signal changes, and then the precision of increase X-ray sensing panel with payment scanning signal potential, it is to avoid the interpretation to sensing result impacts.Additionally, the compensation circuit that the present invention is above-mentioned, simple in construction, can compensate in the case of not increasing circuit complexity.

Although the present invention discloses as above with preferred embodiment; so it is not limited to the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when making a little amendment and perfect, therefore protection scope of the present invention is when with being as the criterion that claims are defined.

Claims (10)

1. an X-ray sensing panel, comprises:

A plurality of data lines；

Multi-strip scanning line；

Multiple pixel elements, are configured to a matrix array, and the plurality of pixel element is coupled to this corresponding data wire and this scan line, in order to produce a sensing signal；

Multiple integrator circuits, the plurality of integrator circuit comprises an operational amplifier, and an inverting input of this operational amplifier is coupled to this corresponding data wire, in order to receive this sensing signal via this data wire；

Multiple compensation circuit, the plurality of compensation circuit is coupled to a non-inverting input of this corresponding operational amplifier, in order to provide a compensation signal to this corresponding integrator circuit.

2. X-ray sensing panel as claimed in claim 1, it is characterised in that this compensation circuit comprises:

One electric capacity, is coupled to this non-inverting input of this operational amplifier；

One alternating-current voltage source, is coupled to this electric capacity；And

One switch, is coupled between this non-inverting input and this alternating-current voltage source of this operational amplifier.

3. X-ray sensing panel as claimed in claim 2, it is characterised in that this pixel element comprises:

One photodiode, in order to produce this sensing signal according to an optical signal；And

One transistor, has one first end, one second end and one and controls end, and this first end is coupled to this photodiode, and this second end is coupled to this integrator circuit, and this control end is in order to receive scan signal.

4. X-ray sensing panel as claimed in claim 3, it is characterised in that during this scanning signal is changed over a rising of a high potential by an electronegative potential, this switch is conducting, and compensating signal is a negative voltage signal.

5. X-ray sensing panel as claimed in claim 3, it is characterised in that during this scanning signal is changed over a decline of an electronegative potential by a high potential, this switch is conducting, and this compensation signal is a forward voltage signal.

6. X-ray sensing panel as claimed in claim 3, it is characterised in that the period outside during declining with one during a rising of the current potential change of this scanning signal, this switch is cut out, and this compensation signal is a DC bias signal.

7. X-ray sensing panel as claimed in claim 3 a, it is characterised in that magnitude of voltage of this alternating-current voltage source is determined by least one parasitic capacitance of this transistor.

8. X-ray sensing panel as claimed in claim 3 a, it is characterised in that capacitance of this electric capacity is determined by least one parasitic capacitance of this transistor.

9. X-ray sensing panel as claimed in claim 1, it is characterised in that X-ray sensing panel also comprises:

One scintillator (scintillator), in order to be converted to a visible light signal by an X-ray signal.

10. X-ray sensing panel as claimed in claim 1, it is characterised in that X-ray sensing panel further includes:

Scan driving circuit, in order to provide scan signal to the plurality of pixel element via the plurality of scan line.