KR102581638B1 - retina image processing device and the Method thereof - Google Patents

Abstract

A retinal image processing device according to an embodiment of the present invention includes an antenna provided on a contact lens platform and receiving an RF wireless signal of image data transmitted from an external camera; A power harvester provided on the contact lens platform and rectifying the RF wireless signal received by the antenna into a DC signal and outputting it as an optical signal; And it is characterized in that it includes a retinal nerve circuit that is inserted into the retina and generates a current signal in response to light incident from the power harvester.

Description

Retina image processing device and the Method thereof}

The present invention relates to a retinal image processing device and method. In particular, the present invention relates to a retinal image processing device for the visually impaired, which includes an antenna for receiving an image signal from an external camera on a contact lens and an RF power harvester for generating wireless power. It relates to a retinal image processing device and method that can provide highly efficient power to the retinal nerve circuit by configuring a retinal nerve circuit (inside the body) formed outside the body and inside the eye.

A neural circuit is a circuit designed similar to the mechanism of nerve cells connected to the human brain. Therefore, neural circuits are designed by imitating human biological mechanisms, and are designed by imitating the structure of neurons, which are basic human neural circuits.

Human information processing involves the brain receiving and processing information recognized by sense organs through neurons.

Visual neuroscience is a field of science that studies the human visual system and implements artificial devices that mimic the mechanisms of the visual system.

Visual neuroscience aims to determine how biological vision is achieved by understanding the input and output connection patterns of cells such as the retina that make up the human visual system, and studying how signals are received, processed, stored, and converted by cells. It is a task.

Based on these research results, one of the things that mimics the human visual system is the retinal nerve circuit. This retinal nerve circuit requires the development of a structure that increases the resolution of the acquired image and has a stable output signal.

Meanwhile, batteries are generally used to supply power to sensors or devices that are implanted in the body and detect or stimulate nervous tissue. However, since sensors or devices that are implanted in the body and sense or stimulate nervous tissue are small and lightweight, the size of the battery used here is also very small. Because the battery size is small, the utilization time of the sensor or device is very short. As a way to solve this problem, a wireless power transmission method that transmits power wirelessly from the outside is suitable.

This wireless power supply is called RF energy harvesting, which supplies energy using RF signals in environments where wired electricity cannot be supplied or battery replacement is difficult. Since the RF signal received through the antenna is an alternating current (AC) voltage, an AC-DC converter, or rectifier, is needed to convert it to direct current (DC) voltage required by most electronic components.

In order to efficiently transfer the harvested energy to devices and at the same time use it in semiconductors, etc., rectifiers are required to be miniaturized.

Additionally, because the harvested energy is very low power, the rectifier must be designed to have high efficiency. Additionally, the additional circuit that controls the rectifier should be simple to be easy to design and should not require a separate external auxiliary battery.

Korean Patent Application No. 10-2019-0127145

The present invention relates to a retinal image processing device for the visually impaired, which includes an external part of the body including an antenna for receiving image signals from an external camera in a contact lens and an RF power harvester for generating wireless power, and a retinal nerve circuit (body) formed inside the eye. The purpose is to provide a retinal image processing device and method that can provide high-efficiency power to a retinal neural circuit by configuring a retinal neural circuit.

However, the technical challenge that this embodiment aims to achieve is not limited to the technical challenges described above, and other technical challenges may exist.

As a technical means for achieving the above-described technical problem, a retinal image processing device according to an embodiment of the present invention includes an antenna provided on a contact lens platform and receiving an RF wireless signal of image data transmitted from an external camera; A power harvester provided on the contact lens platform and rectifying the RF wireless signal received by the antenna into a DC signal and outputting it as an optical signal; And it is characterized in that it includes a retinal nerve circuit that is inserted into the retina and generates a current signal in response to light incident from the power harvester.

Here, in particular, the power harvester includes a coupling capacitor for alternating current-coupling the RF wireless signal; A multi-stage rectifier that receives the AC signal output from the coupling capacitor and rectifies it into a DC signal; and a filtering unit that filters the DC signal rectified in the multi-stage rectifier.

Here, the power harvester is particularly characterized in that it further includes a micro light emitting diode (μ-LED) that outputs the DC signal filtered by the filtering unit as an optical signal.

Here, in particular, the multi-stage rectifier is configured by connecting a first stage and a second stage, and each RF wireless signal input terminal of the first stage and the second stage includes coupling capacitors (C1 to C4) for AC-coupling. Its characteristic lies in the fact that it does so.

Here, it is particularly characterized in that C1 and C2 are connected to the input terminal of the first stage, and C3 and C4 are connected to the input terminal of the second stage.

Here, in particular, the output terminal of C1 is connected to the gate of M1 and the source of M2, the output terminal of C2 is connected to the gate of M3 and the source of M4, and the output terminal of C3 is connected to the gate of M1' and the source of M2'. It is connected to the source of, and the output terminal of C4 is characterized in that it is connected to the gate of M3' and the source of M4'.

Here, in particular, a C5 capacitor is included between the gate of M4' and ground, and the C5 capacitor is characterized in that it uniformly maintains the DC component of the signal output from the second stage.

Here, in particular, the retinal neural circuit includes a current generator that generates a current in response to incident light; A current mirror that outputs a current of the same magnitude as the current input from the current generator; and a feedback circuit that returns a signal input from the current mirror to the current generator, and the feedback circuit includes a component that controls the magnitude of the voltage output from the current mirror.

Here, in particular, the current generation unit includes a photodiode that generates current in response to incident light; a first capacitor in which charge is accumulated by the current generated from the photodiode; and a first amplifier circuit that generates a first output voltage that is the output voltage of the current generator and is a preset value.

Here, the output signal of the feedback circuit is particularly characterized in that it is input to the first amplifier circuit.

Here, the current mirror is particularly characterized in that it receives the first output voltage from the first amplifier circuit and outputs a second output voltage.

Here, the feedback circuit is particularly characterized in that it controls the current mirror so that the second output voltage is output at a preset value.

Here, the second output voltage is particularly characterized in that it is generated by light input to the photodiode and a control voltage input to the current mirror.

Here, in particular, the feedback circuit includes a transistor that amplifies the input voltage; and

It is characterized by including a second capacitor that is connected to the transistor and accumulates charge by the input current.

In addition, as a technical means for achieving the above-described technical problem, a retinal image processing method according to an embodiment of the present invention includes receiving an RF wireless signal of image data transmitted from an external camera at an antenna of a contact lens platform; Rectifying the RF wireless signal received by the antenna in a power harvester into a DC signal and outputting it as an optical signal; and generating a current signal in response to light incident from the power harvester in a retinal neural circuit inserted into the retina.

Here, in particular, the step of outputting an optical signal from the power harvester includes AC-coupling the received RF wireless signal; receiving the alternating current-coupling AC signal and rectifying it into a DC signal; filtering the rectified DC signal; and outputting the filtered DC signal as an optical signal.

Here, in particular, the step of generating a current signal in response to the incident light includes generating a current in response to the incident light in a current generator; Outputting a current of the same magnitude as the generated current from a current mirror; And it is characterized in that it includes a step of receiving the output current from a feedback circuit, controlling the magnitude of the voltage, and returning it to the current generator.

According to one of the means for solving the problems of the present invention described above, an optical signal is transmitted from the outside of the body to the inside of the body, and the nerve signal generates an optic nerve action potential in response to the intensity of the optical signal for the image, thereby transmitting image information to the brain. In a retinal image processing device, high-efficiency power can be harvested from outside the body (contact lens) without a separate power source and power can be provided semi-permanently.

Figure 1 is a diagram schematically showing the overall configuration of a retinal image processing device according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing the configuration of the retinal image processing device of FIG. 1.
FIG. 3 is a circuit diagram schematically showing the configuration of the power harvester of the retinal image processing device of FIG. 2.
Figures 4a to 4c are graphs showing changes in power values obtained according to frequency in the power harvester of the present invention.
Figure 5 is a graph showing the change in efficiency according to the output power of the present invention.
FIG. 6 is a circuit diagram schematically showing the configuration of the retinal neural circuit of FIG. 2.
Figure 7 is a diagram schematically showing a flow chart for the retinal image processing method according to the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention, parts unrelated to the description have been omitted from the drawings, and similar parts have been assigned similar reference numerals throughout the specification. In addition, while explaining with reference to the drawings, even if the configuration is shown with the same name, the drawing number may vary depending on the drawing, and the drawing number is merely written for convenience of explanation, and the concept, feature, and function of each component are determined by the drawing number. Alternatively, the effect is not interpreted as limited.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected," but also the case where it is "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, this does not mean excluding other components unless specifically stated to the contrary, but may further include other components, and means that it may further include one or more other components. It should be understood that this does not exclude in advance the possibility of the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof.

In this specification, 'part' or 'module' includes a unit realized by hardware or software, and a unit realized using both, and one unit is realized using two or more hardware. This may be possible, or two or more units may be realized by one hardware.

FIG. 1 is a diagram schematically showing the overall configuration of a retinal image processing device according to an embodiment of the present invention, and FIG. 2 is a diagram schematically showing the configuration of the retinal image processing device of FIG. 1.

As shown in FIGS. 1 and 2, the retinal image processing device 10 of the present invention is provided on a contact lens platform 11 and receives image data captured from an external camera 400 via RF (radio frequency) wireless. Antenna 100 that receives signals; A power harvester 200 provided on the contact lens platform 11 and rectifying the RF wireless signal received from the antenna 100 into a direct current (DC) voltage and outputting it as an optical signal; and a retinal nerve circuit 300 that is inserted into the retina and generates a current signal in response to light incident from the power harvester 200.

The antenna 100 is a small electric loop microstrip antenna that can be configured on a contact lens platform to receive RF images without being implanted within the eye.

More specifically, all devices implanted within human tissue must be designed in a frequency-limited band that is harmless to the human body. In other words, the frequency band that is harmless to the human body can be limited to the permitted ultra-wideband (UWB) frequency band of 3.1GHz to 10.6GHz. Here, it is desirable to design the UWB antenna to be applicable to small size, low power consumption, high bit rate, and highly integrated systems. For example, a small loop antenna can be placed in a glass contact lens.

The power harvester 200 is configured on the contact lens platform 11, and the retinal neural circuit 300 is configured as an implant in the inner retina of the eye, between the contact lens platform 11 and the artificial retinal neural circuit 300. Power and data transmission methods mainly use optical signals, and optical signals are information data for acquiring images on the retina.

More specifically, the power harvester 200 rectifies the RF signal, which is an AC signal transmitted from the antenna 100, into a DC voltage and outputs it as an optical signal. Here, the power harvester 200 supplies DC power to the customized micro light emitting diode (μ-LED) 230. At this time, the micro light emitting diode (μ-LED) 230 mainly transmits light signals by emitting light.

Here, for a detailed description of the power harvester 200, refer to FIGS. 3 to 5, which will be described later.

The retinal nerve circuit 300 receives the optical signal transmitted from the micro light emitting diode (μ-LED) 230 from the photo diode 310, and the light passes through ganglion, amacrine, bipolar, horizontal cells and photoreceptors. This stimulates the photoreceptors and converts them into electrical signals. Photoreceptors generate signals that are transmitted to ganglion cells through the middle layer of neurons.

Afterwards, the information from the transmitted signal is propagated to the optic nerve and then to the brain in the form of an action potential. At this time, action potentials in the form of output spikes are generated by the neuron retinal circuit. Here, for a detailed description of the retinal nerve circuit 300, refer to FIG. 6, which will be described later.

Meanwhile, FIG. 3 is a circuit diagram schematically showing the configuration of the power harvester of the retinal image processing device of FIG. 2.

As shown in FIG. 3, the power harvester 200 includes a multi-stage rectifier 210 that receives the AC signal, which is the RF wireless signal, and rectifies it into a DC signal; A filtering unit 220 that filters the DC signal rectified in the multi-stage rectifier 210; and a micro light emitting diode (μ-LED) 230 that outputs the DC signal filtered by the filtering unit as an optical signal.

The multi-stage rectifier 210 is composed of a first stage 211 and a second stage 212 connected, and each RF wireless signal input terminal of the first stage 211 and the second stage 212 has an AC-couple It can be configured to include coupling capacitors (C1 to C4) that ring.

Additionally, the first stage 211 can be configured by connecting M1 to M4 PMOS transistors, and the second stage 212 can be configured by connecting M1' to M4' PMOS transistors.

More specifically, coupling capacitors C1 and C2 for AC-coupling RF wireless signals are connected to the input terminal of the first stage 211.

And, the output terminal of C1 is connected to the gate of M1 and the source of M2, and the output terminal of C2 is connected to the gate of M3 and the source of M4.

Additionally, coupling capacitors (C3 and C4) for AC-coupling the RF wireless signal are connected to the input terminal of the second stage 212.

The output terminal of C3 is connected to the gate of M1' and the source of M2', and the output terminal of C4 is connected to the gate of M3' and the source of M4'.

Additionally, a C5 capacitor is connected between the gate of M4' and ground, and the C5 capacitor can maintain the DC component of the signal output from the second stage 212 uniformly.

Here, in the M1 to M4 PMOS transistors of the first stage 211 of the multi-stage rectifier 210 of the present invention and the M1' to M4' PMOS (P-channel metal oxide semiconducto) transistors of the second stage 212, P-type Metal oxide semiconductors (PMOS) can operate at low thresholds by connecting the body terminal to the source to eliminate body effects, improving the sensitivity of the rectifier.

Equation 1 below represents the threshold voltage of the forward bias of the PMOS transistor.

[Equation 1]

Here, V _th0p is the threshold voltage of 0 when the substrate voltage (V _sb ) is 0, γ is the body effect coefficient, 2Ψ _F is the surface potential, and represents the potential difference between the source and body of the MOSFET.

At this time, V _th0p , γ, and 2Ψ _F are values transmitted during the manufacturing process and cannot be arbitrarily changed because they are values determined by the doping concentration of the silicon substrate, the amount of charge in the depletion region, and the work function of the silicon substrate.

However, the threshold voltage of the MOSFET can be arbitrarily adjusted during circuit design through V _SB , the potential difference between the source and body.

Additionally, the calculation at each stage of the drain current operation considered for the PMOS transistor can be expressed as Equation 2 below.

[Equation 2]

Where, V _d is the drain voltage, I _ds is the current through the channel of the transistor with negative direction, W is the channel width from drain to source, L is the channel length, Ψ _t is the thermal voltage, equal to 26 mV at room temperature, and n represents the slope coefficient, respectively.

The filtering unit 220 makes it possible to obtain a smooth and adjusted DC output from mW to W by the output of a T-shaped filtering network.

Meanwhile, Figures 4A to 4C are graphs showing changes in power values obtained according to frequency in the power harvester of the present invention.

As shown in Figures 4a to 4c, the output is shown according to the frequency range, and the 2.7W output at 4mW shows a power efficiency of 40% to 82%.

That is, Figure 4a shows outputs of 4mW to 7.5mW, 7mW to 0.1mW, and 0mW to 2.7W in the frequency bands of 3GHz to 5.5GHz, Figure 4b to 5.5GHz to 7.5GHz, and Figure 4c to 7.5GHz to 10.5GHz, respectively.

Figure 5 is a graph showing the change in efficiency according to the output power of the present invention.

As shown in Figure 5, it can be seen that the efficiency increases linearly as the output power increases from mW to W. Since this forms a multi-stack structure of the power harvester, it is effective in reducing power loss and parasitic interconnections.

Therefore, through the above-described multi-stage rectifier, a compromise can be made through design balance between output voltage and impedance matching, and high efficiency power can be obtained by preventing additional DC voltage loss through the output of the first and second stages. .

Meanwhile, FIG. 6 is a circuit diagram schematically showing the configuration of the retinal neural circuit of FIG. 2. As shown in FIG. 6, the retinal nerve circuit 300 includes current generators 310, 320, and 330 that generate current in response to incident light; A current mirror 340 that outputs a current of the same magnitude as the current input from the current generators 310, 320, and 330; and a feedback circuit 350 that returns the signal input from the current mirror 340 to the current generators 310, 320, and 330, and the feedback circuit 350 receives the signal from the current mirror 340. It may include a configuration that controls the magnitude of the output voltage.

The current generators 310, 320, and 330 include a photodiode 310 that generates current in response to light incident on the retinal nerve circuit; A first capacitor 320 in which charge is accumulated by the current generated by the photodiode 310; and a first amplifier circuit 320 that is the output voltage of the current generators 310, 320, and 330 and generates a first output voltage that is a preset value.

The photodiode 310 is a device that changes light energy into electrical energy, and therefore can generate current in response to incident light. When light is incident on the photodiode 310, current flows through the photodiode 310.

The first capacitor 320 may accumulate charge by the current generated by the photodiode 310. The charge accumulated in the first capacitor 320 is discharged from the first capacitor 320 as the first amplifier circuit 330 is turned on and operated, and the first amplifier circuit 330 is turned off again. ), charges may be accumulated again as light enters the photodiode 110.

The first input voltage (Vi) input to the first amplifier circuit 330 may increase proportionally according to the amount of charge accumulated in the first capacitor 320. In the retinal nerve circuit of the embodiment, the first amplifier circuit 330 can be turned off until the first input voltage (Vi) reaches the switch voltage that operates the first amplifier circuit 330.

When the charge is accumulated in the first capacitor 320 and the first input voltage (Vi) reaches the switch voltage, the first amplifier circuit 330 is turned on and the first input voltage (Vi ) can be input as an input signal, and finally the image information can be output from the retinal nerve circuit as a pulse voltage signal in a step waveform with the same voltage as the second output voltage (Vout).

Accordingly, the retinal nerve circuit of the embodiment may output image information as a step waveform voltage signal using the first capacitor 320. As described above, the step waveform voltage signal can increase the resolution of the acquired image compared to the wave waveform or sine waveform voltage signal.

The first amplifier circuit 330 can generate a first output voltage (Vo), which is the output voltage of the current generator and is a preset value. Accordingly, image information may be input to the first amplifier circuit 330 as a first input voltage (Vi) and output as a first output voltage (Vo).

The current mirror 340 receives the first output voltage from the first amplifier circuit and outputs a second output voltage.

More specifically, the current mirror 340 may include, for example, P-channel MOSFETs M8 and M10 and N-channel MOSFETs M9 and M11. At this time, the control voltage (Vc) can be input to N-channel MOSFET M11.

The second output voltage (Vout) may be generated by light input to the photodiode 310 and a control voltage (Vc) input to the current mirror 340. Therefore, when the control voltage (Vc) is input, the current mirror 200 can output the second output voltage (Vout).

That is, the current mirror 340 can receive the first output voltage (Vo) from the first amplifier circuit 330 and output the second output voltage (Vout), which is the final output signal of the retinal nerve circuit of the embodiment. there is.

The feedback circuit 350 may include a transistor that amplifies the input voltage and a second capacitor 360 that is connected to the transistor and accumulates charge by the input current.

Here, the feedback circuit 350 may be configured to include P-channel MOSFETs M12, M14, M16, and M17 and N-channel MOSFETs M13, M15, and M18. At this time, a second reset pulse (reset2) can be input to the portion where MOSFET M17 and M18 are connected, and a reset voltage (Vreset) can be input to MOSFET M16.

At this time, the second reset pulse (reset2) may be input as a current signal or a voltage signal. The feedback circuit 350 can operate when the second reset pulse (reset2) and reset voltage (Vreset) are input.

The second capacitor 360 is connected to the transistor, and charge can be accumulated by the input current. The role of the second capacitor 360 is the same as that of the first capacitor 320 described above.

That is, the second capacitor 360 sends the step waveform voltage signal from the feedback circuit 350 to the first amplifier circuit 330 of the current generators 310, 320, and 330, thereby generating the second output voltage. By allowing (Vout) to be output as a step waveform, the resolution of the image acquired by the retinal nerve circuit can be increased.

The output signal of the feedback circuit 350 may be input to the first amplifier circuit 330. The output signal of the feedback circuit 350 may be input to MOSFET M2 of the first amplifier circuit 330.

In an embodiment, the first output voltage (Vo) and the second output voltage (Vout) may be output as a pulse waveform. At this time, the first output voltage (Vo) and the second output voltage (Vout) may be preset values.

The feedback circuit 350 can control the second output voltage (Vout), which is the final output signal of the retinal nerve circuit, to remain constant.

Therefore, when the retinal nerve circuit is operating, the current generator 310, 320, 330 or the current mirror 340 malfunctions due to an external electrical shock and the first output voltage (Vo) or the second output voltage (Vout) deviates from the set value. Even so, the second output voltage (Vout) of the retinal nerve circuit can be maintained at a constant value.

Figure 7 is a diagram schematically showing a flow chart for the retinal image processing method according to the present invention. Here, detailed description of each step will be omitted with reference to FIGS. 1 to 6.

As shown in FIG. 7, the RF wireless signal of image data transmitted from an external camera is first received at the antenna of the contact lens platform (S710).

Then, the power harvester rectifies the RF wireless signal received by the antenna into a DC signal and outputs it as an optical signal.

More specifically, the step of AC-coupling the received RF wireless signal (S720) is performed, and the step of receiving the AC-coupled AC signal and rectifying it into a DC signal (S730) is performed.

Next, a step of filtering the rectified DC signal is performed (S740), and the filtered DC signal is output as an optical signal (S750).

In addition, the retinal neural circuit inserted into the retina responds to the light incident from the power harvester and generates a current signal.

More specifically, first, the current generator generates a current in response to the incident light (S760), and then the current mirror outputs a current of the same size as the generated current (S770). , the feedback circuit receives the output current, controls the magnitude of the voltage, and returns it to the current generator (S780).

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: antenna
200: Power Harvester
210: multi-stage rectifier
211: Stage 1
212: Stage 2
220: Filtering unit
230: micro light emitting diode
300: Retinal neural circuit
310: photodiode
330: Amplification circuit
340: current mirror
350: feedback circuit

Claims (18)

An antenna provided on the contact lens platform and receiving an RF (radio frequency) wireless signal of image data transmitted from an external camera;
a power harvester provided on the contact lens platform, which rectifies the RF wireless signal received by the antenna into a direct current (DC) signal and outputs it as an optical signal; and
It includes a retinal nerve circuit that generates a current signal in response to light incident from the power harvester,
The power harvester includes a multi-stage rectifier that receives the RF wireless signal and rectifies it into a DC signal,
The multi-stage rectifier is configured by connecting a first stage and a second stage, and each RF wireless signal input terminal of the first stage and the second stage includes coupling capacitors (C1 to C4) for AC-coupling,
A retinal image processing device in which C1 and C2 are connected to the input terminal of the first stage, and C3 and C4 are connected to the input terminal of the second stage.
According to paragraph 1,
The power harvester,
A retinal image processing device comprising a filtering unit that filters the DC signal rectified in the multi-stage rectifier.
According to paragraph 2,
The power harvester further includes a micro light emitting diode (μ-LED) that outputs the DC signal filtered by the filtering unit as an optical signal.
delete According to paragraph 1,
The first stage is configured by connecting M1 to M4 PMOS (P-channel metal oxide semiconducto) transistors, and the second stage is configured by connecting M1' to M4' PMOS transistors.
delete According to clause 5,
The output terminal of C1 is connected to the gate of M1 and the source of M2, the output terminal of C2 is connected to the gate of M3 and the source of M4, and the output terminal of C3 is connected to the gate of M1' and the source of M2'. A retinal image processing device characterized in that the output terminal of C4 is connected to the gate of M3' and the source of M4'.
In clause 7,
A retinal image processing device comprising a C5 capacitor between the gate of the M4' and ground, wherein the C5 capacitor uniformly maintains the DC component of the signal output from the second stage.
According to paragraph 1,
The retinal neural circuit is,
A current generator that generates current in response to incident light;
A current mirror that outputs a current of the same magnitude as the current input from the current generator; And a feedback circuit that returns the signal input from the current mirror to the current generator,
A retinal image processing device characterized in that the feedback circuit includes a component that controls the magnitude of the voltage output from the current mirror.
According to clause 9,
The current generator,
A photodiode that generates current in response to incident light;
a first capacitor in which charge is accumulated by the current generated from the photodiode; and
A retinal image processing device comprising a first amplifier circuit that generates a first output voltage that is the output voltage of the current generator and is a preset value.
According to clause 10,
A retinal image processing device, characterized in that the output signal of the feedback circuit is input to the first amplifier circuit.
According to clause 11,
The current mirror is,
A retinal image processing device that receives the first output voltage from the first amplifier circuit and outputs a second output voltage.
According to clause 12,
The feedback circuit is,
A retinal image processing device, characterized in that the current mirror is controlled so that the second output voltage is output at a preset value.
According to clause 12,
The second output voltage is,
A retinal image processing device characterized in that it is generated by light input to the photodiode and a control voltage input to the current mirror.
According to clause 9,
The feedback circuit is,
A transistor that amplifies the input voltage; and
A retinal image processing device comprising a second capacitor connected to the transistor and accumulating charge by an input current.
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