Modulation Transfer Function Test Method for TDICMOS

Abstract

This invention relates to a method for testing the modulation transfer function (MJF) of TDICMOS detectors. It addresses the problem of difficulty in identifying and interpreting useful image data during existing MJF testing of TDICMOS detectors. The invention first adjusts the relative position of the detector and target using a planar array mode, and then switches to a linear array mode. The gate transfer control signal of the TDICMOS detector is output normally during the charge transfer phase, but is disabled during the exposure phase. The valid data signal outputs periodic high and low level signals when the gate transfer control signal is present; otherwise, it is a constant level. The charge transfer levels for panchromatic and multispectral images are set to the maximum available levels, and the cyclic frame period length is an integer multiple. Synchronous transmission of panchromatic and multispectral images is ensured, resulting in relatively stable panchromatic and multispectral images in each received frame.

Description

Technical Field

[0001] This invention relates to the field of TDICMOS testing technology, and more specifically to a method for testing the modulation transfer function of multispectral TDICMOS for high-reliability applications. Background Technology

[0002] Although TDICMOS detectors are area array structures, they are typically used as linear array detectors. This makes it inconvenient to directly determine whether the detector's relative position to the target is correct, as the modulation transfer function value has already reached its maximum, or whether the target has been projected onto the specified spectral band. Therefore, using the area array mode of a TDICMOS detector allows for easier determination of relative attitude. For multi-spectral detector applications, panchromatic and multispectral image data are transmitted simultaneously in the same channel. In some modes, several consecutive panchromatic line cycles may be needed to transmit all multispectral image data for a single line. If image data is continuously output during the exposure phase in area array mode, a large portion of the scrolling image data received on the fast view is invalid, with only a partial validity, making it difficult to identify and interpret useful image data. Summary of the Invention

[0003] This invention addresses the problem of difficulty in identifying and interpreting useful image data during modulation transfer function testing of existing TDICMOS detectors by providing a method for testing the modulation transfer function of TDICMOS.

[0004] The modulation transfer function testing system for a TDICMOS detector mainly includes a camera controller, an imaging controller, a TDICMOS detector, a 2711 chip, a 2711 connector, a detector driver chip, a six-dimensional adjustment frame, a lens, and a dynamic target generator. The camera controller communicates with the imaging controller via a 422 communication control signal to control the operating mode and status. The signal output from the imaging controller, after passing through the detector driver chip, provides a drive control signal to the TDICMOS detector; it also receives serial image data output from the TDICMOS detector. The dynamic target generator generates a target image that is projected onto the TDICMOS detector through the lens; the TDICMOS detector, placed on the six-dimensional adjustment frame, allows for attitude and distance adjustments.

[0005] The beneficial effects of this invention are:

[0006] 1. In the method described in this invention, the gate transfer control signal of the TDICMOS detector is output normally during the charge transfer stage, but is prohibited from being output during the exposure stage; this ensures that the detector can continue to work, and the effective exposure time can be extended.

[0007] 2. In the method described in this invention, the valid data signal outputs periodic high and low level signals when there is a gate transfer control signal, and otherwise it is a constant level; this ensures that only useful images are displayed on the fast view, which is convenient for identification and interpretation.

[0008] 3. In the method described in this invention, the charge transfer order of panchromatic and multispectral images is set to the maximum available order, and the cyclic frame period length is an integer multiple. This ensures synchronous transmission of panchromatic and multispectral images, and the panchromatic and multispectral images in each received frame are relatively stable. Attached Figure Description

[0009] Figure 1 This is a block diagram illustrating the principle of the modulation transfer function testing system for the TDICMOS detector described in this invention. Detailed Implementation

[0010] like Figure 1 As shown, the modulation transfer function test system for a TDICMOS detector includes a camera controller, an imaging controller, a TDICMOS detector, a 2711 chip, a 2711 connector, a detector driver chip, a six-dimensional adjustment frame, a lens, and a dynamic target generator.

[0011] The camera controller communicates with the imaging controller via a 422 communication control signal to control the operating mode and status. The signal output from the imaging controller is sent to the TDICMOS detector as a drive control signal after passing through the detector driver chip; it also receives serial image data output from the TDICMOS detector. The dynamic target transmitter generates a target image that is imaged onto the TDICMOS detector after passing through the lens; the TDICMOS detector is placed on a six-dimensional adjustment frame, allowing for attitude and distance adjustments.

[0012] The specific testing method is as follows:

[0013] Step 1: The camera controller controls the imaging controller via a 422 communication control signal, activating it in area array mode. The dynamic target generator remains stationary. The attitude and position of the TDICMOS detector are adjusted, and the static modulation transfer function is measured, ultimately adjusting to the position where the transfer function value reaches its maximum. The specific states of the TDICMOS detector's area array mode are as follows:

[0014] 1. TDICMOS detector multispectral line period length T line_mul_period The full-color line cycle length T line_qs_periodIn working mode 1 (where the multispectral row period length is m times the panchromatic row period length), the number of rows in the full-spectral array mode is m times the number of rows in the multispectral array mode; in working mode 2 (where the multispectral row period length is n times the panchromatic row period length), the number of rows in the full-spectral array mode is n times the number of rows in the multispectral array mode.

[0015]

[0016] The frame period (including the frame period for panchromatic and multispectral sensors) of a TDICMOS detector. frame_period From charge transfer stage T charge_transfer and exposure phase T exposure Composition, consisting of a multispectral line period length T line_mul_period The lengths of the charge transfer and exposure phases are integer multiples of the multispectral line period length; that is, the step size for adjusting the exposure time length is the multispectral line period length T. line_mul_period .

[0017]

[0018] 2. Under different exposure time applications, the frame period lengths of panchromatic and multispectral applications are integer multiples of each other, while the frame period length T of multispectral applications is different. mul_frame_period It can be an integer multiple of the full color, T qs_frame_period =αT mul_frame_period The frame period length T of the full color qs_frame_period It can also be an integer multiple of the multispectral range, T mul_frame_period =βT qs_frame_period α and β refer to the multiples of the panchromatic frame period relative to the multispectral frame period, and the multiples of the multispectral frame period relative to the panchromatic frame period, respectively.

[0019] 3. Panchromatic and multispectral image data share the same 2711 transmission channel, but occupy different bit positions;

[0020] 4. The valid data signal outputs a constant low level during the exposure phase, while during the charge transfer phase, it outputs a periodic signal with varying high and low levels. The control method for the valid data signal is as follows: The valid data signal is generated by a valid data counter. The counter increments when its count value is not greater than p, and remains constant at p until the high level of the backup signal SYNC_BEI (the synchronization signal before valid data is received) is reached. SYNC_BEI is controlled by a cyclic counter in area array mode. It is high when its count value is q, and low at other positions. During the charge transfer phase, the cyclic counter in area array mode cycles between 0 and "current line period length - 1", while during the exposure phase, the count value remains constant at "current line period length - 1".

[0021] 5. The gate transfer control signal is controlled by the cycle counter in the area array mode. During the charge transfer stage, the output shows the normal linear array working mode timing of the TDICMOS detector. The charge transfer in the photosensitive area and the charge transfer in the light-blocking area are periodic signals with high and low level changes. During the exposure stage, the gate transfer control signal outputs a constant level, which is the same as the level value at the end of the line cycle count (the corresponding count value of the cycle counter in the area array mode is "current line cycle length - 1").

[0022] Step 2: The camera controller controls the imaging controller via 422 communication control signals to make it work in the linear array mode; the dynamic target generator sets the rotation speed according to the line period of the TDICMOS detector, and then measures the dynamic transfer function based on the edge method.

[0023] In this embodiment, the detector driver chip uses the 164245 chip from the 58th Research Institute; the TDICMOS detector uses a custom product from Changguang Chenxin Company; the camera controller mainly uses a DSP chip; the imaging controller mainly uses an FPGA and refresh chip from Shanghai Fudan Microelectronics Company; the six-dimensional adjustment frame and lens use off-the-shelf products; the 2711 chip uses the TLK2711 chip; the 2711 connector uses a micro coaxial connector from Sichuan Huafeng; and the dynamic target generator uses a crescent-shaped target generator based on the rotation of the tilting mirror angle.

Claims

1. A method for testing the modulation transfer function of a TDICMOS, characterized by: This method is implemented by the following steps: Step 1: The camera controller controls the imaging controller via 422 communication control signals to make it work in the area array mode; the dynamic target generator is in a stationary state, and the attitude and position of the TDICMOS detector are adjusted and the static modulation transfer function is measured, and finally adjusted to the position where the transfer function value reaches the maximum value; The TDICMOS detector operates in area array mode as follows: TDICMOS detector multispectral row period length The full-color line cycle length In working mode 1: when the multispectral row period length is m times the panchromatic row period length, the number of rows in the full spectrum is m times the number of multispectral rows in the area array mode; in working mode 2: when the multispectral row period length is n times the panchromatic row period length, the number of rows in the full spectrum is n times the number of multispectral rows. Frame period of TDICMOS detector Multispectral line period length Integer multiples of; From the charge transfer stage and exposure phase The composition, charge transfer stage, and exposure stage lengths are integer multiples of the multispectral line period length; the exposure time length adjustment step size is the multispectral line period length. ; These can be expressed as follows: ； In the formula, and These are the multiples of the relative multispectral line period length for the charge transfer stage and the exposure stage, respectively; The valid data signal outputs a constant low level during the exposure phase and a periodic signal with varying high and low levels during the charge transfer phase. Step 2: The camera controller controls the imaging controller via 422 communication control signals to make it work in the linear array mode; the dynamic target generator sets the rotation speed according to the line period of the TDICMOS detector, and then measures the dynamic transfer function based on the edge method.

2. The method for testing the modulation transfer function of TDICMOS according to claim 1, characterized in that: At different exposure times, the frame period length of the full-spectrum band and the frame period length of the multispectral band are integer multiples of each other, i.e., the frame period length of the multispectral band is... It is an integer multiple of the frame period length of the entire chromatographic segment or the frame period length of the entire chromatographic segment. Integer multiples of the frame period length of the multispectral system.

3. The method for testing the modulation transfer function of TDICMOS according to claim 1, characterized in that: Full-spectral image data and multispectral image data share the same 2711 transmission channel, but occupy different bit positions.

4. The method for testing the modulation transfer function of TDICMOS according to claim 1, characterized in that: The control method for the valid data signal is as follows: The imaging controller is internally equipped with a data validity counter and an area array mode cycle counter. The data validity signal is generated by the data validity counter. When the count value of the data validity counter is less than or equal to p, it increments. When it is equal to p, it maintains the count value p until it reaches a high level, at which point it is cleared. The backup signal SYNC_BEI of the synchronization signal SYNC before receiving valid data is controlled by the area array mode cycle counter. When the count value of the data validity counter is q, it is at a high level, and at other positions, it is at a low level. During the charge transfer stage, the count value of the area array mode cycle counter changes cyclically from 0 to the current line cycle length - 1. During the exposure stage, the count value is constant at the current line cycle length - 1.

5. The method for testing the modulation transfer function of TDICMOS according to claim 4, characterized in that: The gate transfer control signal is controlled by the cyclic counter of the area array mode. During the charge transfer stage, the output of the normal linear array working mode timing of the TDICMOS detector is used. The charge transfer of the photosensitive area and the charge transfer of the light-blocking area are periodic signals with high and low level changes. During the exposure phase, the gate transfer control signal outputs a constant level, which is the same as the level value at the end of the line cycle count.

6. The method for testing the modulation transfer function of TDICMOS according to any one of claims 1-5, characterized in that: The testing method is implemented through a testing system, which includes a camera controller, an imaging controller, a TDICMOS detector, a 2711 chip, a 2711 connector, a detector driver chip, a lens, and a dynamic target generator. The camera controller communicates with the imaging controller via a 422 communication control signal to control the working mode and working state; the signal output by the imaging controller is transmitted to the TDICMOS detector via the detector driver chip as a drive control signal; and it receives the serial image data output by the TDICMOS detector; the dynamic target transmitter generates a target that is imaged onto the TDICMOS detector by the lens.

7. The method for testing the modulation transfer function of TDICMOS according to claim 6, characterized in that: It also includes a six-dimensional adjustment frame, on which the TDICMOS detector is placed for attitude and distance adjustment.

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