Comparison Epson WorkForce DS-1630 vs Kodak i1220

— Tablet. In such scanners, the material to be scanned is placed over a special glass surface, under which a photo sensor moves; the original itself does not move. Flatbed models are the most "omnivorous": they have no restrictions on the thickness of the scanned material and usually allow you to work not only with individual sheets, but also with pages and covers of books and magazines, product labels, etc. Their disadvantage is their significant dimensions — the working surface of the scanner must be no smaller than the supported format (see "Format").

— Lengthy. In pull- through scanners, the photo sensor is stationary, and the scanned material moves relative to it using the feed mechanism. They are much more compact than tablet counterparts (see above), because. of the requirements for the dimensions of the scanner in this case, in fact, only the width remains. Such scanners make it much easier to process long materials; in addition, they are often equipped with automatic document feeders(see below for more details), which makes it much easier to work with a large amount of materials. On the other hand, the feed mechanism can only work with single sheets and will not cope with books and other bulky media.

— Tablet / lingering. The most versatile models that combine the advantages of both designs. They have both an open...ing lid with a glass surface below it, which allows you to work with bulky media (like flatbed models), and a transport mechanism that makes it easier to work with long originals and single sheets (like in broaching designs). They are equipped with two optical sensors and in some cases you can even use both at the same time. The disadvantages of such scanners are significant cost and dimensions, and therefore they are usually used in the professional field, where you often have to scan large volumes of dissimilar materials.

— Slide scanner. These scanners differ from all previous types due to the peculiarities of the processed originals — they are designed to work with transparent materials (slides), such as photographic film. Other scanners equipped with slide modules (see "Slide module") can work with slides, but it is specialized models that provide the best quality.

— Manual. The name of this type is due to the fact that such a scanner must be manually moved over the scanned surface during operation. This is not as convenient as using flatbed or broaching models (see above), especially when working with a large amount of materials. At the same time, the dimensions of hand-held scanners are even smaller than those of broaching ones, while they do not have such a drawback as a limitation on the thickness of the processed materials. Such a device can "take" an image even from a large object that cannot be placed in a flatbed scanner — for example, a box.

— CIS, abbreviation for "Contact Image Sensor" — contact image sensor. The simplest type of optical element: it is a line across the entire width of the scanner's working space, on which photocells that read the image and LEDs that provide illumination are located in a row. They are inexpensive and take up little space, which, accordingly, makes the scanners themselves cheaper and smaller. On the other hand, CIS sensors have a shallow depth of field, and even small bumps in the scanned image can be out of focus. However, in general, they are quite suitable for both personal and not too complex professional tasks.

— CCD, short for "Charge-Coupled Device" — a charge-coupled device. A much more complex design than CIS, includes a fluorescent lamp, lens and mirror. CCD scanners are larger, heavier and much more expensive than their counterparts in CIS. On the other hand, this type of optical element provides high-quality colour reproduction and a good depth of field, coping well with complex-shaped media. Therefore, advanced professional scanners are usually equipped with a CCD.

— CMOS. The abbreviation for "Complementary Metal-Oxide-Semiconductor" is a complementary metal-oxide-semiconductor structure (the designation CMOS is also used in Russian). A key feature of CMOS sensors is that they capture the scanned image as a whole, similar to photography (and not...line by line, as in other types of optical elements). In fairness, it should be noted that the "instantaneous" scanning does not give a tangible advantage in speed, because. processing the captured image takes quite a long time. However, this feature is extremely useful in cases where it is difficult to ensure the immobility of the scanned material and/or uniform movement of the optical element relative to this material. Such situations often arise when working with book and handheld scanners (see "Type"), so CMOS elements are most popular in such devices.

The maximum image size that the scanner can process at one time, both horizontally and vertically. You should pay attention to this parameter if you need the exact dimensions of the scanner's working area, down to a millimetre: although standard formats are used to designate these dimensions (see "Format"), in fact the dimensions may differ from them.

The black and white scanning speed provided by the device. Usually, the maximum processing speed for an A4 sheet is indicated, i.e. speed at the lowest resolution. In fact, the speed is usually lower and depends on both the resolution and the size of the original material. The higher the scanning speed, the more convenient it is to work with the scanner; pay special attention to this parameter if you plan to work with numerous black and white images.

Colour scanning speed provided by the device. In fact, it depends on the selected resolution, colour depth and original dimensions; the characteristics most often indicate the speed for an A4 sheet at the minimum resolution and colour depth, i.e. maximum possible speed. If you only need to scan one or more sheets from time to time, high speed is not too critical, but for working with a large amount of materials, you should look for fast models.

Availability of duplex scanning function in the device. Duplex scanning in this case means such an operating mode in which the scanner simultaneously captures an image from both sides of the processed medium (sheet of paper). The convenience of this feature is obvious: the media does not have to be turned over to scan each side separately, and the processing time is significantly reduced. Double-sided scanning is found mainly in the models of traction or combined type (see above), however, there are also flatbed scanners with this capability.

The scanner has its own display. Such displays can vary from simple indicators that display a minimum of service information (selected mode, work process, some errors, etc.) to full-colour touch screens that significantly expand the capabilities of the device. Anyway, the display makes the operation of the scanner more convenient and intuitive.

The maximum noise level produced by the scanner during operation. Theoretically, the lower this parameter, the more comfortable the use of the device, however, the vast majority of scanners have a noise level much lower than the general sound background in a small office (this background is 40-50 dB). Therefore, it is worth paying special attention to the noise level if you plan to use the device at home at a later time, or in other environments where even a slight noise may be undesirable.