WO2012140703A1

WO2012140703A1 - Image-removing device and video display device

Info

Publication number: WO2012140703A1
Application number: PCT/JP2011/004205
Authority: WO
Inventors: 毛利　浩喜; 中平　博幸; 孝一永野; 宏行手塚; 角野　英之
Original assignee: パナソニック株式会社
Priority date: 2011-04-14
Filing date: 2011-07-26
Publication date: 2012-10-18

Abstract

The present invention improves the accuracy with which orthogonality error and amplitude error are corrected. This image-removing device has a correction unit for correcting orthogonality error and amplitude error in an input complex signal, and a complex filter for attenuating and outputting a component of an image frequency in relation to a desired signal in the complex signal following correction. The correction unit has: an adaptive processor for performing the correction using a coefficient and using an adaptive algorithm to update the coefficient used in the correction and obtain a post-convergence coefficient; a bandpass filter for transmitting, from among the frequency components of the corrected complex signal, a component that lies within the frequency range of the desired signal; a power-measuring unit for obtaining the power of the component transmitted through the bandpass filter; and a coefficient searching unit for varying the coefficient used in the correction in a range on a complex plane that includes the post-convergence coefficient, and performing a search process for obtaining a new coefficient in which the power is further reduced. The adaptive processor performs the correction using the new coefficient.

Description

Image removing device and video display device

This disclosure relates to a technique for suppressing the influence of an image signal in a signal obtained by mixing a high-frequency signal and a local oscillation signal.

A receiver that performs quadrature detection by multiplying a received high-frequency signal by a local oscillation signal that is a complex signal by a mixer, and processes the obtained complex signal after quadrature detection is well known. The in-phase signal and quadrature signal of the complex signal after quadrature detection are ideally equal in amplitude and orthogonal. However, in reality, there may be a quadrature and amplitude error (also called IQ imbalance) between the in-phase signal and the quadrature signal. When such an error exists, the desired signal is affected by the image signal in the complex signal after quadrature detection, and the quality of the desired signal is deteriorated. In order to prevent this, for example, Patent Document 1 describes a frequency converter that adjusts the levels of an in-phase signal and a quadrature signal output from a mixer.

JP 2002-246847 A

However, as in Patent Document 1, just adjusting the levels of the in-phase signal and the quadrature signal using an LMS (least mean square) algorithm does not necessarily mean that the levels of these signals become optimum values. If the levels of the in-phase signal and the quadrature signal are not appropriate values, the quadrature error and the amplitude error are not sufficiently corrected, so that the influence of the image signal on the desired signal cannot be sufficiently suppressed.

An object of the present invention is to improve the correction accuracy of orthogonality error and amplitude error.

An image removal apparatus according to the present disclosure corrects an orthogonality error and an amplitude error of an input complex signal, outputs a corrected complex signal, and an image frequency component for a desired signal in the corrected complex signal And a complex filter for outputting the obtained signal. The correction unit performs the correction using a coefficient, updates the coefficient used for the correction by an adaptive algorithm and obtains a converged coefficient, and among the frequency components of the corrected complex signal, A bandpass filter that passes a component in the frequency band of the desired signal, a power measurement unit that obtains power of the component that has passed through the bandpass filter, and a coefficient used for the correction is a complex including the coefficient after convergence. And a coefficient search unit that performs a first search process for obtaining a new coefficient for reducing the power by changing within a first region on the plane. The adaptive processing unit performs the correction using the new coefficient.

The video display device according to the present disclosure includes the image removal device and a display that displays video based on a signal output from the complex filter.

According to the present disclosure, since the orthogonality error and the amplitude error can be corrected with higher accuracy, the influence of the image signal on the desired signal can be sufficiently suppressed.

FIG. 1 is a block diagram illustrating a configuration example of a video display device according to an embodiment of the present invention. FIG. 2A is a diagram illustrating an example of vectors corresponding to signal points of a desired signal and an image signal on the complex plane when there is no IQ imbalance. FIG. 2B is a diagram illustrating an example of vectors corresponding to signal points of the desired signal and the image signal on the complex plane when there is IQ imbalance. FIG. 3A is a spectrum diagram corresponding to FIG. FIG. 3B is a spectrum diagram corresponding to FIG. FIG. 4 is a block diagram illustrating a configuration example of the correction unit in FIG. FIG. 5 is a diagram illustrating an example of values that can be taken by the coefficient W in the region in which the coefficient W changes during the first search process. FIG. 6 is a diagram illustrating an example of a search order in the first search process. FIG. 7 is a diagram illustrating an example of search ranges and order in the second search process. FIG. 8 is a diagram illustrating an example of the relationship between the coefficient W and the SN ratio. FIG. 9 is an example of a state transition diagram for the coefficient search unit of FIG. FIG. 10 is a diagram illustrating another example of the search order in the first search process. FIG. 11 is a diagram illustrating another example of the search order in the second search process. FIG. 12 is a diagram illustrating still another example of the search order in the first search process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components shown with the same reference numbers in the drawings are identical or similar components.

FIG. 1 is a block diagram showing a configuration example of a video display apparatus according to an embodiment of the present invention. The video display device 100 in FIG. 1 includes a receiver 110, a display 72, and a speaker 74. The receiver 110 includes an amplifier (LNA) 14,

mixers

15, 16, 61 and 62,

oscillators

17 and 63, phase shifters 18 and 64, an IF (intermediate frequency) unit 20, and a decimation filter. 65 and 66 and a DSP (digital signal processor) 68. The IF unit 20 includes an analog complex filter 22, analog-to-digital converters (ADCs) 23 and 24, a digital inverse characteristic filter 26, a correction unit 30, and a digital complex filter 52. The correction unit 30 and the digital complex filter 52 operate as an image removal device. Although not particularly illustrated, the video display device 100 of FIG. 1 has a control unit, and the control unit controls the components of the device of FIG.

The LNA 14 amplifies and outputs an RF (radio frequency) signal received by the antenna 12. The oscillator 17 generates and outputs a signal LR having a frequency LO necessary for converting the RF signal into an IF signal. The phase shifter 18 delays the phase of the signal LR generated by the oscillator 17 by 90 ° and outputs the delayed signal. The mixer 15 multiplies the signal amplified by the LNA 14 by the signal LR and outputs the signal AI. The mixer 16 multiplies the signal amplified by the LNA 14 by the signal output from the phase shifter 18 and outputs the result as a signal AQ.

The analog complex filter 22 converts the desired signal included in the complex signal AC (consisting of the signals AI and AQ) into a complex signal AC so that the signal level near the image frequency becomes small (for example, 30 dB lower). Processing is performed on the signal and output as a complex signal FC (consisting of signals FI and FQ). This is to make the complex signal AC fall within the dynamic range of the

ADCs

23 and 24.

ADCs

23 and 24 convert the signals FI and FQ into digital signals, respectively, and output them. The digital inverse characteristic filter 26 has an inverse characteristic of the analog complex filter 22. The digital inverse characteristic filter 26 performs processing to cancel the influence of the analog complex filter 22 on the output signals of the

ADCs

23 and 24, and outputs the result as a complex signal RC (consisting of signals RI and RQ). .

The correction unit 30 corrects the orthogonality error and the amplitude error of the input complex signal RC to the correction unit 30 and outputs the corrected complex signal CC (consisting of signals CI and CQ) to the digital complex filter 52. . The digital complex filter 52 attenuates an image frequency component with respect to a desired signal in the complex signal CC, and outputs a complex signal DC (composed of signals DI and DQ) in which the image frequency component is attenuated.

The oscillator 63 generates and outputs a signal LS having a frequency necessary for converting the IF signal into a baseband signal. The phase shifter 64 delays the phase of the signal LS generated by the oscillator 63 by 90 ° and outputs the delayed signal. The mixer 61 multiplies the signal DI by the signal LS and outputs it. The mixer 62 multiplies the signal DQ by the signal output from the phase shifter 64 and outputs the result.

The decimation filter 65 outputs the output signal of the mixer 61 after thinning the sample value. The decimation filter 66 outputs the output signal of the mixer 62 after thinning the sample value. The DSP 68 performs predetermined signal processing on the output signals of the

decimation filters

65 and 66 and outputs the obtained video signal and audio signal. The display 72 displays video based on the video signal output from the DSP 68. The speaker 74 outputs sound based on the sound signal output from the DSP 68.

1 receives, for example, an FM (frequency modulation) radio broadcast signal, but may receive other radio broadcast signals, television broadcast signals, and signals such as mobile phones.

FIG. 2A is a diagram illustrating an example of vectors corresponding to signal points of a desired signal and an image signal on the complex plane when there is no IQ imbalance. FIG. 2B is a diagram illustrating an example of vectors corresponding to signal points of the desired signal and the image signal on the complex plane when there is IQ imbalance. 2A and 2B show the complex signal AC after quadrature detection. When there is no IQ imbalance, the desired signal D and the image signal U do not interfere as shown in FIG. On the other hand, when there is IQ imbalance, an image leak having the same phase as the desired signal D occurs as shown in FIG. 2B, and this interferes with the desired signal D.

FIG. 3 (a) is a spectrum diagram corresponding to FIG. 2 (a). FIG. 3B is a spectrum diagram corresponding to FIG. When there is no IQ imbalance, as shown in FIG. 3A, the desired signal D and the image signal U are separated by the frequency 2f_IF and do not interfere with each other. When there is IQ imbalance, an image leak due to the image signal is superimposed on the desired signal D as shown in FIG. For this reason, the power of the frequency component near the desired signal D is greater in the case of FIG. 3B than in the case of FIG. That is, when there is no IQ imbalance, the power of the frequency component near the desired signal D is minimized.

FIG. 4 is a block diagram illustrating a configuration example of the correction unit 30 in FIG. As illustrated in FIG. 4, the correction unit 30 includes an adaptive processing unit 32, a bandpass filter (BPF) 42, a power measurement unit 44, and a coefficient search unit 46. The adaptive processing unit 32 includes a multiplier 34, a subtracter 36, and a coefficient update unit 38. The thick line in FIG. 4 represents a complex signal. A complex signal RC (in-phase signal RI and quadrature signal RQ) is input to the subtractor 36. The multiplier 34 receives the complex signal RCC. The complex signal RCC includes an in-phase signal RI and a signal obtained by inverting the sign of the quadrature signal RQ, and is in a complex conjugate relationship with the complex signal RC.

The adaptive processing unit 32 corrects the orthogonality error and the amplitude error of the complex signal RC using the coefficient W to reduce the IQ imbalance. The adaptation processing unit 32 is an LMS algorithm that is one of adaptation algorithms,
u = Y−w × Y ^* (1)
w (k + 1) = w (k) + μ × u (k) ² (k is a natural number) (2)
To update the coefficient W. Here, u, w, Y, and Y ^* correspond to the complex signal CC, the coefficient W, and the complex signals RC and RCC, respectively. μ is a predetermined step size.

Specifically, the multiplier 34 multiplies the complex signal RCC by the coefficient W and outputs the result. The subtracter 36 subtracts the output signal of the multiplier 34 from the complex signal RC, and outputs the subtraction result as a corrected complex signal CC (Equation (1)). The coefficient updating unit 38 obtains a new coefficient W (k + 1) based on the complex signal CC and the previous coefficient W (k), and outputs the new coefficient W (k + 1) to the multiplier 34 and the coefficient searching unit 46 (Equation (2)). The multiplier 34, the subtractor 36, and the coefficient updating unit 38 repeat the above operation until the coefficient W converges to obtain the converged coefficient W0.

The band-pass filter 42 passes the components in the frequency band of the desired signal among the frequency components of the complex signal CC and attenuates other frequency components. The power measuring unit 44 obtains the power of the component that has passed through the bandpass filter 42 and outputs it to the coefficient searching unit 46. The power required by the power measurement unit 44 is an average power obtained by averaging instantaneous power or instantaneous power of two or more samples. Hereinafter, as an example, the power measurement unit 44 will be described as obtaining average power.

After the coefficient W converges to the coefficient W0 by the adaptive algorithm, the coefficient search unit 46 performs a first search process. In the first search process, the coefficient W is changed in a region on the complex plane including the converged coefficient W0 obtained by the coefficient updating unit 38, and a new power obtained by the power measuring unit 44 becomes smaller. This is a process for obtaining the coefficient W1. For example, the coefficient search unit 46 obtains the number that minimizes the power in this region as a new coefficient W1.

FIG. 5 is a diagram illustrating an example of values that can be taken by the coefficient W in the region in which the coefficient W changes during the first search process. The horizontal axis is the real axis, and the vertical axis is the imaginary axis. In the following description, it is assumed that the coefficient W converges to the coefficient W0 = (real part, imaginary part) = (0.625, 0.625) by the adaptive algorithm. The area in FIG. 5 is an area having a predetermined width and height centered on the coefficient W0, but may be another area including the coefficient W0. In the case of FIG. 5, the real part of the coefficient W has a value of 0.375, 0.500, 0.625, 0.750, and 0.875, and the imaginary part of the coefficient W is also 0.375, 0. The value is any of 500, 0.625, 0.750, and 0.875.

Thus, the region of FIG. 5 can be obtained within this region as the sum of one real number that differs by 0.125 (first step) and one imaginary number that differs by 0.125 (second step). Contains multiple complex numbers that can. The coefficient search unit 46 changes the coefficient W used for correction among these complex numbers during the first search process.

FIG. 6 is a diagram illustrating an example of a search order in the first search process. Each square in the region R1 in FIG. 6 is the same as that shown in FIG. For example, as shown in FIG. 6, the coefficient search unit 46 moves from the left end (W = (0.375, 0.375)) to the right end (W = (0.875, 0.375)) in the uppermost row in the region R1. The search is performed by changing the real part of the coefficient W by 0.125, and then the imaginary part of the coefficient W is changed by 0.125 to search from the left end to the right end of the next row. Similarly, all the cells in FIG. 6 are searched. If it is found that the power obtained by the power measurement unit 44 is minimized when the coefficient W is W1, the coefficient search unit 46 holds the coefficient W1 as a result of the first search process. In this way, the coefficient search unit 46 changes the real part of the coefficient W in units of 0.125 and changes the imaginary part of the coefficient W in units of 0.125 within the region of FIG. The unit may be other values.

FIG. 7 is a diagram illustrating an example of search ranges and order in the second search process. After the first search process, the coefficient search unit 46 performs a second search process. In the second search process, the coefficient W is changed in the region R2 on the complex plane including the coefficient W1 obtained in the first search process, and a new coefficient W2 in which the power obtained by the power measurement unit 44 becomes smaller. Is a process for obtaining. The region R2 for the second search process in FIG. 7 is narrower than the region R1 for the first search process in FIG.

The region R2 in FIG. 7 is a sum of one real number that differs by a third step (eg, 0.03) smaller than the first step and one imaginary number that differs by a fourth step (eg, 0.03) smaller than the second step. Includes a plurality of complex numbers that can be obtained in this region. In the second search process, the coefficient search unit 46 changes the coefficient W used for correction among these complex numbers.

For example, the coefficient search unit 46 searches from the left end of the uppermost row to the right end in the region R2 in FIG. 7, and then searches from the left end to the right end of the lower row. At this time, the coefficient search unit 46 sets the coefficient W to the value of each cell. Similarly, all the cells in the area for the second search process are searched. If the coefficient search unit 46 finds that the power obtained by the power measurement unit 44 is minimized when the coefficient W is W2, the coefficient search unit 46 holds the coefficient W2 as a result of the second search process.

FIG. 8 is a diagram showing an example of the relationship between the coefficient W and the SN (signal-to-noise) ratio. FIG. 8 shows a result obtained by simulation, and shows an example in the case where the optimum value of the coefficient W is in a region different from FIG. In FIG. 8, the S / N ratio is minimized in the vicinity of the point indicating the coefficient W2, and the S / N ratio increases as it approaches the periphery of FIG. The S / N ratio is the ratio of the desired signal to the noise in the input signal of the power measurement unit 44. Assuming that the noise is constant, the S / N ratio is shown with a diagram showing the power obtained by the signal power measurement unit 44. Since the figure is the same, the S / N ratio is shown here. The point indicating the coefficient W2 obtained by further performing the first and second search processing is more suitable for the SN ratio and the power of the input signal of the power measuring unit 44 than the point indicating the coefficient W0 obtained only by the adaptive algorithm. It can be seen from FIG. 8 that is smaller and is a more appropriate value.

That is, since the coefficient search unit 46 performs the first and second search processes, a more appropriate coefficient W2 can be obtained as the coefficient W. By correcting the complex signal RC using the coefficient W2, a complex signal CC having a smaller IQ imbalance can be obtained.

FIG. 9 is an example of a state transition diagram for the coefficient search unit 46 of FIG. The coefficient search unit 46 has a frequency switching detection state, a rough search state, a fine search state, and a standby state. The coarse search state corresponds to the first search process, and the fine search state corresponds to the second search process. The coefficient search unit 46 includes an internal counter and a search counter. In addition to the description in FIG. 9, the counter is also reset when the edge of the frequency switching flag is detected, when transitioning to a different state, and when the counter reaches a predetermined value.

The frequency switching flag, the image detection flag, the DU ratio detection flag, the search start flag, and the internal generation flag are generated by the control unit. The frequency switching flag is a flag for notifying that the reception frequency has been changed at the time of tuning or the like, and rises at the time of switching. The image detection flag is a flag that notifies the presence / absence of an image frequency signal. The image detection flag becomes a high logic level when the level of the image frequency signal is equal to or higher than a predetermined threshold and the DU ratio (ratio of the desired signal to the image signal) is within a predetermined range. The DU ratio detection flag becomes a high logic level when the DU ratio is equal to or greater than a predetermined threshold. The search start flag controls the start and stop of the search by the coefficient search unit 46. The internal generation flag is a logical product of the image detection flag and the DU ratio detection flag.

As shown in FIG. 9, the coefficient search unit 46 operates as follows. The coefficient search unit 46 performs the first search process again when notified by the frequency switching flag that the reception frequency has been changed. The coefficient search unit 46 repeats the first search process and then repeats the second search process every predetermined time. The coefficient search unit 46 does not perform the first search process when notified by the image detection flag that there is no image frequency signal. The coefficient search unit 46 stops the first search process when notified by the image detection flag that there is no image frequency signal during the first search process. After that, when notified by the image detection flag that the image frequency signal exists, the coefficient search unit 46 resumes the first search process.

FIG. 10 is a diagram illustrating another example of the search order in the first search process. Similarly to FIG. 6, the coefficient search unit 46 searches from the left end of the uppermost row to the right end in the region R1, and then searches from the left end to the right end of the lower row. However, at this time, the coefficient search unit 46 first searches every other square (only the shaded portion in FIG. 10). When the search to the lower right of FIG. 10 is completed, the process returns to the beginning, and the remaining cells are searched in the same order.

FIG. 11 is a diagram illustrating another example of the search order in the second search process. As in FIG. 7, the coefficient search unit 46 searches from the left end of the uppermost row to the right end in the region R2, and then searches from the left end to the right end of the lower row. However, the coefficient search unit 46 first searches every other square (only the shaded portion in FIG. 11). When the search to the lower right of FIG. 11 is completed, the process returns to the beginning, and the remaining cells are searched in the same order. In FIGS. 10 and 11, the case where one cell is searched for every two has been described. However, one cell is searched for every n (n is an integer of 2 or more), and then the entire region R1 or R2 is searched. The search for one square for every n squares that have not yet been searched may be repeated in the entire region R1 or R2. When one cell is searched for every n pieces as shown in FIG. 10 or FIG. 11, an appropriate coefficient W1 or W2 is obtained quickly, and the response performance of the receiver is improved.

FIG. 12 is a diagram showing still another example of the search order in the first search process. The coefficient search unit 46 searches the range of FIG. 12 in a spiral shape from the periphery, for example. In other words, the coefficient search unit 46 sequentially searches for values closest to the boundary of the range of FIG. 12, and then sequentially searches for values inside these values. Similarly, the inner value is searched for. Conversely, the coefficient search unit 46 may search in a spiral shape from the center.

In the above embodiment, the case where the first and second search processes are performed after the coefficient W has converged to the coefficient W0 by the adaptive algorithm has been described. However, after the convergence, the coefficient search unit 46 performs only the first search process. You may do it. The coefficient search unit 46 may be stopped according to the situation. As a result, power consumption can be reduced, and when the coefficient search unit 46 is stopped, an unnecessary circuit does not operate, so that signal degradation (noise and distortion) can be suppressed.

Each functional block in this specification can be typically realized by hardware. For example, each functional block can be formed on a semiconductor substrate as part of an IC (integrated circuit). Here, the IC includes an LSI (large-scale integrated circuit), an ASIC (application-specific integrated circuit), a gate array, an FPGA (field programmable gate array), and the like. Alternatively, some or all of each functional block can be implemented in software. For example, such a functional block can be realized by a processor and a program executed on the processor. In other words, each functional block described in the present specification may be realized by hardware, may be realized by software, or may be realized by any combination of hardware and software.

Many features and advantages of the present invention will be apparent from the written description, and thus, it is intended by the appended claims to cover all such features and advantages of the present invention. Further, since many changes and modifications will readily occur to those skilled in the art, the present invention should not be limited to the exact construction and operation as illustrated and described. Accordingly, all suitable modifications and equivalents are intended to be within the scope of the present invention.

As described above, according to the present disclosure, it is possible to improve the correction accuracy of the orthogonality error and the amplitude error. Therefore, the present invention is useful for an image removal device, a video display device, and the like.

30 Correction Unit 32 Adaptive Processing Unit 34 Multiplier 36 Subtractor 38 Coefficient Update Unit 42 Band Pass Filter 44 Power Measurement Unit 46 Coefficient Search Unit 52 Digital Complex Filter (Complex Filter)
100 video display device

Claims

A correction unit that corrects the orthogonality error and amplitude error of the input complex signal and outputs the corrected complex signal;
A complex filter for attenuating an image frequency component for a desired signal in the complex signal after correction and outputting the obtained signal;
The correction unit is
An adaptive processing unit that performs the correction using a coefficient, updates the coefficient used for the correction by an adaptive algorithm, and obtains a converged coefficient;
Of the frequency components of the complex signal after correction, a bandpass filter that passes components in the frequency band of the desired signal;
A power measurement unit for obtaining power of a component that has passed through the bandpass filter;
A coefficient search unit that performs a first search process for changing a coefficient used for the correction in a first region on a complex plane including the converged coefficient to obtain a new coefficient that reduces the power; Have
The adaptive processing unit is an image removal device that performs the correction using the new coefficient.
The image removal apparatus according to claim 1,
The adaptive processing unit includes:
A coefficient updating unit that updates a coefficient used for the correction based on the corrected complex signal;
A multiplier for multiplying the complex signal in a complex conjugate relationship with the input complex signal by the updated coefficient and outputting a signal after multiplication;
An image removing apparatus comprising: a subtracter that subtracts the multiplied signal from the input complex signal and outputs the signal as the corrected complex signal.
The image removal apparatus according to claim 1,
In the first search process, the coefficient search unit can obtain a plurality of complex numbers that can be obtained in the first region as a sum of one real number that differs for each first step and one imaginary number that differs for each second step. An image removing device for changing a coefficient used for the correction.
The image removal apparatus according to claim 3.
The coefficient search unit changes the real part of the coefficient used for the correction from the first real value to the second real value step by step in the first region, and the coefficient used for the correction. An image removing apparatus that repeats changing the imaginary part in the second step.
The image removal apparatus according to claim 3.
The coefficient search unit changes the real part of the coefficient used for the correction from the first real value to the second real value by n times (n is an integer of 2 or more) of the first step in the first region. And an image removing device that repeats changing the imaginary part of the coefficient used for the correction in the second step.
The image removal apparatus according to claim 3.
The coefficient search unit is an image removal device that searches in a spiral shape in the first region.
The image removal apparatus according to claim 3.
The coefficient search unit, after the first search process, within the second region that includes the new coefficient and is narrower than the first region, the second step is different from one of the real numbers that is different by a third step that is smaller than the first step. A coefficient used for the correction is changed among a plurality of complex numbers that can be obtained as a sum of one different imaginary number for each smaller fourth step, and a coefficient with smaller power is obtained as the new coefficient. An image removing device that performs the second search process.
The image removal apparatus according to claim 7.
When the coefficient search unit is notified that the reception frequency has been changed, the image search device performs the first search process again.
The image removal apparatus according to claim 8, wherein
The coefficient search unit performs the first search process again and then repeats the second search process every predetermined time.
The image removal apparatus according to claim 1,
The image search apparatus, in which the coefficient search unit does not perform the first search process when notified that there is no image frequency signal.
The image removal apparatus according to claim 1,
The coefficient search unit is an image removal device that stops the first search process when notified that there is no image frequency signal during the first search process.
12. The image removal device according to claim 11, wherein
The image search device restarts the first search process when the coefficient search unit is notified that a signal having an image frequency exists.
The image removal apparatus according to claim 1,
The image removing apparatus, wherein the adaptive algorithm is an LMS (least mean square) algorithm.
An image removal device according to claim 1;
An image display device comprising: a display that displays an image based on a signal output from the complex filter.