What Is a Digital (Video) Microscope?
A digital microscope (or video microscope) is an instrument used to magnify an object for observation. However, the term digital microscope generally refers to a microscope equipped with a digital camera and is distinguished from an optical video microscope. Compared to optical video microscopes, digital microscopes have a deeper depth of focus and the ability to measure angles and lengths, which are their main features.
An optical microscope has two lenses, an objective lens, and an eyepiece, while digital microscopes have only an objective lens, and the part corresponding to the eyepiece lens is a digital camera. This can be said to be the most significant difference between an optical microscope and a digital microscope. The digital microscope usually projects the observed object on a monitor.
Several models are available from various manufacturers, with magnifications ranging from several times to several thousand times.
Uses of Digital Microscopes
Video microscopes are used not only for magnifying and observing objects but also for evaluations and analyses based on the obtained image data.
They have been introduced in varied fields such as the automotive and aviation industries, the electronic device industries, the medical and cosmetic industries, and the chemical and material industries, and are used in a wide range of applications from research and development to quality assurance.
For example, in failure analysis of electronic components, digital microscopes can be used to inspect the appearance of IC chips, analyze failures of defective products, inspect foreign objects, and analyze their size and shape.
Principle of Digital Microscopes
In a digital microscope, an object is magnified by an optical lens (objective lens), and the part that corresponds to the human eye in optical microscopes is a digital camera. The image magnified by the optical lens is detected by the image sensor and the image is displayed on a monitor.
The magnifying power of optical microscopes is expressed as the product of the magnifying power of the objective lens and the eyepiece. In the case of digital microscopes, however, the size of the monitor and the size of the image sensor of the camera affect the magnifying power, which is different from the concept of magnifying power of optical video microscopes. Digital microscope’s magnification is also expressed as the product of the magnification of the objective lens and the magnification of the monitor. The magnifying power of the monitor is calculated by dividing the monitor size by the image sensor size.
In addition to magnification, resolution, or the ability to distinguish details, it is necessary to observe an object in greater detail. If the resolution is not sufficient, the observed image will be blurred and details cannot be observed clearly. In the case of digital microscopes, the resolution of the objective lens, the resolution of the optical lens of the digital camera, the resolution of the image sensor, and the resolution of the monitor all affect the resolution.
It is necessary to select a model that provides optimal magnification and resolution according to the object to be observed and the purpose. To meet user requirements for these advanced resolution processing capabilities, 4K monitor-type images have recently been introduced.
Other Information About Digital Microscopes
1. Use of Digital Microscopes in Dentistry
One of the applications of digital microscopes is in dentistry. By taking advantage of the focusing function of digital microscopes, it is possible to observe minute-affected areas that are difficult to detect with the naked eye.
In particular, when performing root canal therapy, which is the complete removal of caries, digital microscopes are used to make it possible for the dentist to remove as much of the affected area as possible.
The use of digital microscopes improves the quality of treatment and reduces the risk of recurrence due to overlooked areas. However, it should be noted that dental treatment using video microscopes is, in principle, not covered by insurance and must be paid out-of-pocket.
2. Cosmetic Use of Digital Microscopes
Digital microscopes are also used for cosmetic-related treatments and diagnoses, such as cosmetic surgery and scalp checkups. By looking at the skin under microscopic magnification, details such as dryness of the skin and the development of the hairline can be observed.
Clients undergoing cosmetic surgery can also gain a sense of satisfaction from the medical examination by being able to check the condition of their skin and scalp on the screen. It also motivates the client to improve their condition.
3. Examples of Functions of the Latest Digital Microscopes
Digital microscopes are nowadays often used for detailed analysis of the inside of electronic components and semiconductor ICs down to a few microns, replacing scanning electron microscopes (SEM), which require observation in a vacuum. For this purpose, for practical use, it is necessary to increase magnification and resolution by orders of magnitude from a few millimeters to a few microns during observation.
This operation requires changing the objective lens as in optical video microscopes, but some digital microscopes in recent years have built-in automatic rotation for lens change and automatic focusing function for lens change, making this process almost fully automatic.
In terms of image processing, there are now highly functional types that can combine images with high magnification into a single large image by arranging them vertically and horizontally like tatami mats, and that can process an object into a three-dimensional (3D) image by utilizing the image focus adjustment function.
There are examples where digital microscopes are used to check the wiring of semiconductor ICs and to analyze internal defects in electronic components by combining these functions.
4. Digital Microscope Prices
The price of digital (or video) microscopes varies depending on their applications and performance. Digital microscopes with a narrow range of magnification and field of view start at around 10,000 yen, while those used for beauty molding or simple inspection of the scalp are priced at around 50,000 yen, and those used for medical purposes are in the 100,000 yen or more range.
Furthermore, digital microscopes such as those used for product inspection in the manufacturing industry, such as semiconductor manufacturing, require high magnification and micron-level magnification, high-resolution image display, so the price range is generally in the several million yen range.
Low latency screen display and high frame rate are also important for use in surgery and treatment, but digital microscopes with low latency and high frame rate tend to be priced higher. In addition, there are products on the market that allow the magnification of the display to be enlarged by changing the lens. In this case, the image processing capability is also advanced, and the price increases further due to the need for a dedicated monitor and sophisticated control software.