超大景深三维立体视频显微镜（高端三维物证显微检验系统）司法鉴定与刑事技术合规应用介绍

作者：毕思特科技来源：毕思特科技浏览数：26 发布时间：2026/4/14 9:02:08

超大景深三维立体视频显微镜（高端三维物证显微检验系统）司法鉴定与刑事技术合规应用介绍

【重要合规前置声明】本设备为法庭科学痕迹检验、文件检验、法医物证鉴定专用高端计量级检验仪器，仅面向具备法定痕迹检验、文件检验、法医物证鉴定资质的公安、检察、司法行政、司法鉴定等国家机关及授权鉴定机构定向研发、生产与销售，不向任何个人、无资质企业及非授权单位提供。本设备的采购、安装、使用、校准与维护，必须严格遵守《中华人民共和国刑事诉讼法》《中华人民共和国司法鉴定程序通则》《法庭科学实验室规范》《法庭科学工具痕迹检验规范》《法庭科学文件检验规范》等国家法律法规与行业技术标准，设备需具备公安部认可的产品安全质量检测报告，必须由依法登记的司法鉴定人、刑事技术专业人员规范操作，严禁无资质单位和个人违规使用，严禁因操作不当、数据失真导致的司法鉴定证据失效、案件定性错误。

产品概述

超大景深三维立体视频显微镜（高端三维物证显微检验系统），是一款集成先进光学设计、高精度电动控制与智能图像处理技术的综合性高端物证显微检验平台，专为刑事技术领域痕迹物证的高分辨率、大景深、三维形态观察与精准测量等复杂鉴定任务深度定制。系统通过高倍率复消色差物镜、大范围光学变倍、多模式可控光源照明，搭配专业 Z 轴景深合成与三维建模分析软件，可对工具痕迹、枪弹痕迹、印章印文、笔迹压痕、纤维、微量残留物等各类涉案物证，实现全细节清晰、具备真实立体感的静态与动态观察、高清图像采集与精准定量分析，彻底解决传统光学显微镜高倍率下景深不足、立体痕迹无法完整呈现、测量数据溯源性差的行业痛点，为司法鉴定工作提供直观、精准、可量化、可追溯的科学证据，是刑事技术实验室痕迹检验、文件检验、微量物证鉴定专业的核心高端检验装备。

技术原理

系统基于光学显微成像、数字图像处理与三维形貌重建技术协同工作，三大技术模块共同保障物证检验成像的清晰度、测量的精准度与三维建模的真实性。高分辨率工业摄像头通过高品质复消色差物镜与连续变倍器，获取样品不同焦平面的光学放大高清图像，其核心三维成像与超景深能力来源于两大核心技术路径：一是通过高精度电动 Z 轴调焦机构，驱动物镜沿垂直方向精准步进，在不同焦平面完成多次自动对焦并采集序列图像，通过专业软件的智能算法，将不同焦平面的清晰细节自动融合，生成一张所有细节全程清晰的全景深二维图像，彻底解决高倍率放大下景深不足的问题；二是通过可 ±60° 倾斜的观察支架，配合高精度编码载物台，获取样品不同倾斜角度、不同视场的多组高清图像，通过专业三维重建算法，还原样品表面的真实三维形貌与立体尺寸，生成可 360° 旋转观察、精准三维测量的数字模型。同时系统配备多路可控 LED 光源，包括四分区独立控制的环形光源与内置同轴光源，可提供不同角度、不同亮度的照明模式，精准凸显物证表面的微观纹理、立体压痕、线条痕迹等细微特征，为痕迹特征的识别、比对与测量提供最佳成像条件。

核心功能与合规实战价值

系统配备高品质复消色差 APO 物镜，具备 12 倍至 675 倍的连续放大范围，光学变倍比不小于 16:1，支持有级与无级两种变倍模式，所有倍率变化均可被系统智能编码自动识别，并同步更新测量标尺，确保全倍率范围内测量数据的绝对准确性与溯源性，完全符合司法鉴定机构资质认定、CNAS 实验室认可对测量设备计量溯源性的核心要求，从硬件源头避免因倍率误差、标尺偏差导致的鉴定数据失真，保障鉴定意见的科学性与法庭可采性。

系统实现真正的三维立体观察与超景深高清成像，搭载可 ±60° 倾斜的观察支架与专业三维重建软件，可实现物证样品的立体对观察与三维形貌还原；配合 0.25μm 精度的电动 Z 轴调焦机构，Z 轴有效行程不小于 60mm，通过独有的自动多焦面合成功能，可将不同焦平面的清晰图像合成为全细节清晰的全景深图像，完美适配钳剪痕迹、撬压痕迹、弹头膛线痕迹、笔迹压痕等粗糙、不平整、具有立体起伏的痕迹物证检验需求，可完整保留痕迹的微观三维特征，避免传统显微镜因景深不足导致的细节漏检、特征失真，为痕迹的种类认定与同一认定提供完整、清晰的特征依据。

系统搭载 1000 万物理像素高速工业级高清摄像头，最大图像尺寸不小于 3664×2748，采集帧率不低于 37 帧 / 秒 @1600x1200 分辨率，可实现无拖影、无延迟的高清动态实时观察与图像采集。配套专业检验分析软件集成了强大的测量工具包，支持距离、角度、面积、半径、曲率等几何参数的人工与自动测量，同时具备 2D 大视野图像拼接、灰度分析、智能 HDR、特征标注比对等专业功能，所有测量结果均可自动关联当前倍率、观察角度与设备状态信息，确保测量数据的严谨性与可追溯性；软件内置司法鉴定文书自动生成系统，可直接将检验图像、测量数据、特征比对结果自动导入规范鉴定文书，完全适配公安刑事技术、司法鉴定机构的文书出具规范，大幅提升鉴定工作效率与合规性。

系统实现全流程电动化智能控制与人性化操作设计，载物台 XY 轴移动、±180° 旋转，Z 轴调焦，光源亮度与照明方向均实现电动或数字化控制，所有运行状态均可被软件实时识别、记录与存档，物镜支持热插拔与智能编码自动识别，无需人工校准即可实现参数自动匹配，有效降低人为操作误差，保障不同鉴定人操作流程的一致性与结果的可重复性。系统采用显微镜主机与专用图像处理电脑分离式设计，电脑配置不低于 i5/8G/1T/2G 独显，搭配 27 寸以上 IPS 高清显示器，便于设备的日常维护、系统升级与数据安全管理，同时可完美对接实验室 LIMS 信息管理系统，实现检验流程、原始数据、鉴定报告的全流程可追溯管理，完全符合司法鉴定机构的合规管理要求。

合规应用场景

本设备仅可由具备法定痕迹检验、文件检验、法医物证鉴定资质的机构与司法鉴定人，在授权鉴定业务范围内规范使用，核心合规应用场景包括五大类：一是工具痕迹与枪弹痕迹检验，可清晰呈现钳剪、撬压、打击、擦划等工具痕迹的微观形貌特征、线条接合关系，以及弹头弹壳上的膛线痕迹、击针孔、抛壳挺痕迹的立体形态，为作案工具的种类认定与同一认定提供核心特征依据，是涉枪、涉盗案件侦办与鉴定的关键技术支撑；二是文件检验鉴定，可通过大景深高清成像，清晰观察印章印文的细节特征、笔划交叉顺序、朱墨时序、纸张纤维分布、打印字迹的墨粉堆积形态、书写笔迹的压痕深浅，以及货币、证件、票据上的精细印刷与防伪特征，实现文件真伪鉴别、形成方式与形成时间鉴定，是合同诈骗、票据伪造、印章伪造等案件侦办与鉴定的核心装备；三是指纹与足迹立体特征分析，可对遗留在粗糙表面、有重叠覆盖的疑难潜在指纹进行三维立体观察，增强纹线与背景的反差，完整还原指纹的立体细节特征，同时可对足迹的压痕深浅、磨损特征进行立体测量与形态分析，为指纹比对、足迹追踪与嫌疑人同一认定提供科学依据；四是微量物证与法医物证检验，可对案件现场提取的纤维捻度与截面形态、毛发鳞片结构、油漆碎片的层次与断裂面、玻璃碎屑的边缘特征，以及微小生物组织碎片进行高清晰度形态学观察、测量与记录，为微量物证的种类认定、来源溯源提供关键检验数据；五是爆炸物残留物及特殊痕迹检验，可清晰观察爆炸装置元器件上的加工痕迹、导线熔珠的微观形态、燃烧与烟熏痕迹的表面结构，以及开锁痕迹、破坏痕迹等特殊现场痕迹的微观特征，为爆炸案件、破坏案件的侦办与鉴定提供技术支撑。

核心技术参数

系统光学系统配备带智能编码的复消色差 APO 物镜，放大倍数覆盖 12 倍至 675 倍，光学变倍比不小于 16:1，支持明场、暗场、斜照明多种观察方式。成像系统搭载 1000 万物理像素工业级高清摄像头，最大图像尺寸不小于 3664×2748，图像采集帧率不低于 37 帧 / 秒 @1600x1200 分辨率。机械机构方面，Z 轴调焦为电动控制，调焦精度 0.25μm，有效行程不小于 60mm；载物台 XY 轴有效行程 76×50mm，支持 ±180° 旋转并带位置编码；观察支架可实现 ±60° 倾斜，内置角度传感器与安全报警功能。照明系统配备高亮度环形 LED 光源，支持亮度连续调节与四分区照明角度独立控制，同时内置同轴照明光源。配套专业软件具备自动倍率与标尺识别、超景深图像合成、三维形貌重建、2D 大视野图像拼接功能，支持距离、角度、面积、半径等全参数几何测量、图像分析与鉴定报表自动生成，内置司法鉴定文书自动生成系统，具备公安部认可的产品检测报告与合法使用授权。控制系统采用显微镜主机与专用图像处理电脑分离式设计，电脑配置不低于 i5 处理器 / 8G 内存 / 1T 硬盘 / 2G 独立显卡，搭配 27 寸以上 IPS 高清显示器。

合规实战应用案例

某市公安局刑事技术支队受理一系列跨区域撬盗保险柜案件，犯罪嫌疑人采用特制撬棍暴力撬开保险柜实施盗窃，案发现场仅在保险柜柜门与锁具上提取到多处撬压痕迹与钳剪痕迹，无其他有效生物物证，痕迹检验成为锁定作案工具、串并案件的唯一突破口。传统光学显微镜因高倍率下景深不足，无法完整呈现痕迹的立体线条特征与起伏形貌，多次检验均未获得足够的同一认定特征。检验人员使用本超大景深三维立体视频显微镜，通过多焦面全景深合成功能，生成了痕迹全细节清晰的二维图像，同时通过多角度采集完成了痕迹的三维形貌重建，清晰还原了撬压痕迹上的 12 处独特线条特征、磨损缺口与立体形态，成功将全市 17 起撬盗保险柜案件的现场痕迹进行串并，认定为同一作案工具形成。后续侦查人员抓获犯罪嫌疑人后，在其住处查获了涉案特制撬棍，通过本设备完成了作案工具与现场痕迹的同一认定，出具的痕迹鉴定意见书被法庭全部采纳，形成了完整的证据链，成功破获了该系列跨区域撬盗案件，本设备的超景深成像与三维重建能力，为案件的串并与侦破提供了决定性的科学证据。
某市人民检察院委托司法鉴定中心，对一起涉案金额超千万元的合同诈骗案件中的涉案合同、担保文件进行文件检验鉴定，案件核心争议点为合同上的公司印章印文真伪，以及印章印文与打印字迹的朱墨时序，直接决定案件的定性与涉案金额的认定。由于涉案文件纸张存在褶皱、印文存在部分重叠，传统显微镜无法清晰呈现印文与字迹的交叉层次、印文的三维压痕特征，检验工作一度陷入僵局。鉴定人使用本超大景深三维立体视频显微镜，通过超景深合成功能，清晰呈现了印文与字迹笔划的交叉顺序、印泥的堆积形态与纸张纤维的压痕特征，同时通过三维形貌重建，还原了印章盖印形成的立体压痕与打印字迹的墨粉附着形态，最终出具了 “涉案印章印文系伪造、印文形成时间晚于打印字迹” 的鉴定意见，为检察机关认定合同诈骗犯罪事实提供了核心科学证据，案件顺利提起公诉，伪造印章的犯罪嫌疑人被依法定罪量刑，本设备的高清成像与精准三维测量能力，为疑难文件检验鉴定提供了关键技术支撑，保障了司法鉴定意见的科学性与法律效力。

厂家信息‌：北京毕思特联合科技有限公司

网址：https://www.bestlh.com

‌地址‌：北京市亦庄开发区经海六路一号院尖子班 C9 独栋

‌电话‌：010-56526048

Application Introduction of Ultra-Large Depth of Field 3D Stereo Video Microscope (High-End 3D Forensic Evidence Microscopic Inspection System)

Global site URL：https://xilankeji.en.alibaba.com

【Important Compliance Pre-Declaration】This equipment is a high-end metrological grade inspection instrument dedicated to forensic science tool mark examination, document examination, and forensic material evidence identification. It is only developed, produced and sold for state organs and authorized authentication institutions with legal qualifications of tool mark examination, document examination, and forensic material evidence identification, including public security organs, procuratorates, judicial administrative organs, and judicial authentication institutions, and will not be provided to any individual, unqualified enterprise or non-authorized unit. The procurement, installation, use, calibration and maintenance of this equipment must strictly abide by national laws, regulations and industry technical standards such as the Criminal Procedure Law of the People's Republic of China, General Rules for Judicial Authentication Procedures of the People's Republic of China, Forensic Science Laboratory Specification, Forensic Science Tool Mark Examination Specification, and Forensic Science Document Examination Specification. The equipment must have a product safety and quality inspection report recognized by the Ministry of Public Security, and must be operated in a standardized manner by legally registered judicial appraisers and criminal technology professionals. It is strictly prohibited for unqualified units and individuals to use it in violation of regulations, and it is strictly prohibited to cause invalidation of judicial authentication evidence and wrong case characterization due to improper operation and data distortion.

Product Overview

The Ultra-Large Depth of Field 3D Stereo Video Microscope (High-End 3D Forensic Evidence Microscopic Inspection System) is a comprehensive high-end forensic evidence microscopic inspection platform integrating advanced optical design, high-precision electric control and intelligent image processing technology, which is deeply customized for complex identification tasks in the field of criminal technology that require high-resolution, large depth of field, 3D morphology observation and accurate measurement of trace evidence. Through high-magnification apochromatic objective lens, large-range optical zoom, multi-mode light source illumination, matched with professional Z-axis depth of field synthesis and 3D modeling analysis software, the system can realize extremely clear, real three-dimensional static and dynamic observation, image acquisition and quantitative analysis of various involved evidence such as tool marks, bullet marks, seal impressions, handwriting indentations, fibers, and trace residues. It completely solves the industry pain points of insufficient depth of field, incomplete presentation of three-dimensional traces and poor traceability of measurement data of traditional optical microscopes under high magnification, provides intuitive, accurate, quantifiable and traceable scientific evidence for judicial authentication work, and is the core high-end inspection equipment for trace examination, document examination and trace evidence identification in criminal technology laboratories.

Technical Principle

The system works based on the collaboration of optical microscopic imaging, digital image processing and 3D morphology reconstruction technology. The three technical modules jointly ensure the clarity of forensic evidence inspection imaging, the accuracy of measurement and the authenticity of 3D modeling. The high-resolution industrial camera obtains optically amplified high-definition images of the sample in different focal planes through a high-quality apochromatic objective lens and continuous zoomer. Its core 3D imaging and ultra-depth of field capabilities come from two core technical paths: first, through the high-precision electric Z-axis focusing mechanism, the objective lens is driven to step accurately along the vertical direction, complete automatic focusing multiple times in different focal planes and collect sequence images. Through the intelligent algorithm of professional software, the clear details of different focal planes are automatically fused to generate a full-depth of field 2D image with all details clear throughout, which completely solves the problem of insufficient depth of field under high magnification. Second, through the observation bracket that can be tilted by ±60°, matched with a high-precision coded stage, multiple groups of high-definition images of the sample at different tilt angles and different fields of view are obtained. Through professional 3D reconstruction algorithm, the real 3D morphology and three-dimensional size of the sample surface are restored, and a digital model that can be rotated and observed 360° and accurately measured in three dimensions is generated. At the same time, the system is equipped with multi-channel controllable LED light sources, including a ring light source with four-zone independent control and a built-in coaxial light source, which can provide lighting modes with different angles and brightness, accurately highlight the micro texture, three-dimensional indentation, line traces and other subtle features of the evidence surface, and provide the best imaging conditions for the identification, comparison and measurement of trace features.

Core Functions and Compliance Practical Value

The system is equipped with high-quality apochromatic APO objective lens, with a continuous magnification range from 12 times to 675 times, an optical zoom ratio of no less than 16:1, supporting both stepped and stepless zoom modes. All magnification changes can be automatically identified by the system's intelligent coding, and the measurement scale is updated synchronously, ensuring the absolute accuracy and traceability of measurement data in the full magnification range. It fully complies with the core requirements of qualification certification of judicial authentication institutions and CNAS laboratory accreditation for the metrological traceability of measuring equipment, avoids the distortion of identification data caused by magnification error and scale deviation from the hardware source, and ensures the scientificity and court admissibility of authentication opinions.

The system realizes real three-dimensional observation and ultra-depth of field high-definition imaging, equipped with an observation bracket that can be tilted by ±60° and professional 3D reconstruction software, which can realize stereo pair observation and 3D morphology restoration of evidence samples. Matched with an electric Z-axis focusing mechanism with 0.25μm accuracy, the effective stroke of the Z-axis is no less than 60mm. Through the unique automatic multi-focal plane synthesis function, clear images of different focal planes can be synthesized into a full-detail clear full-depth of field image, which is perfectly suitable for the inspection needs of rough, uneven, three-dimensional undulating trace evidence such as clipper shear marks, prying marks, bullet rifling marks, and handwriting indentations. It can completely retain the micro three-dimensional features of the traces, avoid detail omission and feature distortion caused by insufficient depth of field of traditional microscopes, and provide a complete and clear feature basis for the type identification and individual identification of traces.

The system is equipped with a 10 megapixel physical pixel high-speed industrial-grade high-definition camera, with a maximum image size of no less than 3664×2748, and an acquisition frame rate of no less than 37 frames per second @1600x1200 resolution, which can realize high-definition dynamic real-time observation and image acquisition without smear and delay. The supporting professional inspection and analysis software integrates a powerful measurement tool kit, supports manual and automatic measurement of geometric parameters such as distance, angle, area, radius and curvature, and has professional functions such as 2D large field of view image stitching, grayscale analysis, intelligent HDR, and feature marking and comparison. All measurement results can automatically associate the current magnification, observation angle and equipment status information, ensuring the rigor and traceability of the measurement data. The software has a built-in automatic generation system for judicial authentication documents, which can directly import inspection images, measurement data and feature comparison results into standardized authentication documents, fully adapting to the document issuance specifications of public security criminal technology and judicial authentication institutions, and greatly improving the efficiency and compliance of authentication work.

The system realizes full-process electric intelligent control and humanized operation design. The XY axis movement, ±180° rotation of the stage, Z-axis focusing, light source brightness and illumination direction all realize electric or digital control. All operating states can be identified, recorded and archived by the software in real time. The objective lens supports hot swap and intelligent coding automatic identification, and can realize automatic parameter matching without manual calibration, which effectively reduces manual operation errors and ensures the consistency of operation process and repeatability of results by different appraisers. The system adopts a separate design of the microscope host and a dedicated image processing computer, with a computer configuration of no less than i5 processor/8G memory/1T hard disk/2G independent graphics card, matched with a 27-inch or larger IPS high-definition display, which is convenient for daily maintenance, system upgrade and data security management of the equipment. At the same time, it can be seamlessly connected with the laboratory LIMS information management system, realizing the full-process traceable management of inspection process, original data and identification reports, and fully complying with the compliance management requirements of judicial authentication institutions.

Compliant Application Scenarios

This equipment can only be used in a standardized manner by institutions and judicial appraisers with legal qualifications of tool mark examination, document examination and forensic material evidence identification within the scope of authorized authentication business. The core compliant application scenarios include five categories: First, tool mark and bullet mark examination, which can clearly present the micro morphological features and line joint relationship of tool marks such as clipper shear, prying, striking and scratching, as well as the three-dimensional shape of rifling marks, firing pin holes and ejector marks on bullets and cartridge cases, providing core feature basis for the type identification and individual identification of crime tools, and is the key technical support for the investigation and identification of gun-related and theft-related cases. Second, document examination and identification, through large depth of field high-definition imaging, can clearly observe the detailed features of seal impressions, stroke cross order, ink-seal sequence, paper fiber distribution, toner morphology of printed handwriting, as well as fine printing and anti-counterfeiting features on currency, certificates and bills, realize the authenticity identification of documents, formation method and formation time identification, and is the core equipment for the investigation and identification of contract fraud, bill forgery, seal forgery and other cases. Third, three-dimensional feature analysis of fingerprints and footprints, which can carry out three-dimensional observation of difficult latent fingerprints left on rough surfaces with overlapping coverage, enhance the contrast between ridge lines and background, completely restore the three-dimensional detailed features of fingerprints, and at the same time carry out three-dimensional measurement and morphological analysis of the indentation depth and wear characteristics of footprints, providing a scientific basis for fingerprint comparison, footprint tracking and individual identification of suspects. Fourth, trace evidence and forensic material evidence inspection, which can carry out high-definition morphological observation, measurement and recording of the twist and cross-sectional shape of fibers extracted from the crime scene, hair scale structure, layer and fracture surface of paint fragments, edge features of glass debris, as well as tiny biological tissue fragments, providing key inspection data for the type identification and source traceability of trace evidence. Fifth, explosive residue and special trace inspection, which can clearly observe the processing marks on the components of explosive devices, the micro morphology of wire molten beads, the surface structure of combustion and smoke traces, as well as the micro features of special on-site traces such as unlocking marks and damage marks, providing technical support for the investigation and identification of explosion cases and damage cases.

Core Technical Parameters

The optical system of the system is equipped with an apochromatic APO objective lens with intelligent coding, the magnification covers 12 times to 675 times, the optical zoom ratio is no less than 16:1, and it supports multiple observation modes of bright field, dark field and oblique illumination. The imaging system is equipped with a 10 megapixel physical pixel industrial-grade high-definition camera, the maximum image size is no less than 3664×2748, and the image acquisition frame rate is no less than 37 frames per second @1600x1200 resolution. In terms of mechanical mechanism, the Z-axis focusing is electrically controlled, with a focusing accuracy of 0.25μm and an effective stroke of no less than 60mm; the effective stroke of the stage XY axis is 76×50mm, supporting ±180° rotation with position coding; the observation bracket can realize ±60° tilt, with built-in angle sensor and safety alarm function. The lighting system is equipped with a high-brightness ring LED light source, supporting continuous brightness adjustment and independent control of four-zone illumination angle, as well as a built-in coaxial illumination light source. The supporting professional software has the functions of automatic magnification and scale identification, ultra-depth of field image synthesis, 3D morphology reconstruction, 2D large field of view image stitching, supports full-parameter geometric measurement such as distance, angle, area and radius, image analysis and automatic generation of identification reports, has a built-in automatic generation system for judicial authentication documents, and has a product inspection report recognized by the Ministry of Public Security and legal use authorization. The control system adopts a separate design of the microscope host and a dedicated image processing computer, with a computer configuration of no less than i5 processor/8G memory/1T hard disk/2G independent graphics card, matched with a 27-inch or larger IPS high-definition display.

Practical Application Cases

The Criminal Technology Detachment of the Municipal Public Security Bureau accepted a series of cross-regional safe burglary cases. The suspect used a special crowbar to violently pry open the safe to commit theft. Only multiple prying marks and clipper shear marks were extracted from the safe door and lock at the crime scene, without other effective biological evidence. Trace examination became the only breakthrough to lock the crime tool and link the cases. Due to the insufficient depth of field under high magnification, the traditional optical microscope could not fully present the three-dimensional line features and undulating morphology of the traces, and sufficient individual identification features were not obtained after multiple inspections. The inspectors used this Ultra-Large Depth of Field 3D Stereo Video Microscope, through the multi-focal plane full-depth of field synthesis function, generated a two-dimensional image with clear full details of the traces. At the same time, through multi-angle acquisition, the 3D morphology reconstruction of the traces was completed, which clearly restored 12 unique line features, wear notches and three-dimensional morphology on the prying marks. The on-site traces of 17 safe burglary cases in the city were successfully linked and identified as formed by the same crime tool. After the subsequent investigators arrested the suspect, they seized the special crowbar involved in the case at his residence. Through this equipment, the individual identification of the crime tool and the on-site traces was completed. The issued trace identification opinion was fully adopted by the court, forming a complete evidence chain, and successfully detected the series of cross-regional burglary cases. The ultra-depth of field imaging and 3D reconstruction capabilities of this equipment provided decisive scientific evidence for the linking and detection of the cases.
The People's Procuratorate of a city entrusted the Judicial Authentication Center to conduct document examination and authentication of the contract and guarantee documents involved in a contract fraud case with an involved amount of more than ten million yuan. The core dispute of the case was the authenticity of the company seal impression on the contract, as well as the ink-seal sequence of the seal impression and the printed handwriting, which directly determined the characterization of the case and the determination of the involved amount. Due to the wrinkles of the paper involved in the case and the partial overlap of the seal impression, the traditional microscope could not clearly present the cross level of the seal impression and handwriting, and the three-dimensional indentation characteristics of the seal impression, so the inspection work was once in a deadlock. The judicial appraiser used this Ultra-Large Depth of Field 3D Stereo Video Microscope, through the ultra-depth of field synthesis function, clearly presented the cross order of the seal impression and handwriting strokes, the accumulation form of ink paste and the indentation characteristics of paper fibers. At the same time, through 3D morphology reconstruction, the three-dimensional indentation formed by the seal stamping and the toner attachment form of the printed handwriting were restored. Finally, the authentication opinion that "the seal impression involved in the case is forged, and the formation time of the seal impression is later than the printed handwriting" was issued, which provided core scientific evidence for the procuratorate to determine the facts of contract fraud. The case was successfully prosecuted, and the suspect who forged the seal was convicted and sentenced according to law. The high-definition imaging and accurate 3D measurement capabilities of this equipment provided key technical support for the difficult document examination and authentication, and ensured the scientificity and legal effect of the judicial authentication opinion.