Sharp calculators with Dynamic Scattering Mode (DSM) Liquid Crystal Displays
Sharp was one of the pioneers of calculators using the DSM (Dynamic Scattering Mode) LCD (Liquid Crystal Display). These DSM LCDs have the now unusual feature of silver-like reflective digits on a dark background, rather than the now common black digits on a light background.
Although Sharp was one of the pioneers of LCD displays, Rockwell is usually credited with producing the first commercial LCD calculators the previous year, 1972, though these required an internal light source and were much larger; see the Lloyds Accumatic 100. However, Rockwell quit LCD calculators after a few models whereas Sharp persisted with the development of LCD displays and later produced many models with the now familiar LCD with black digits.
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'COS' technology
Some of these DSM LCD calculators also employ Sharp's 'COS' (Crystal on Substrate) technology. This is a method of manufacture used in the early Sharp LCD calculators where the LCD is formed directly on a glass circuit board substrate (see the close-up photographs below) on which the other electronic components are also mounted. Some subsequent Sharp models with the reflective DSM LCD, although not having the LCD directly formed on the circuit board, are also commonly referred to, incorrectly, as 'COS' models.
The following details of the development of COS and the Sharp EL-805 are based on information kindly supplied by Sharp Corporation:
'A development team headed by Isamu Washozuka had been engaged in developing LCD devices for calculators. Although Rockwell had already produced some large, desktop, AC-powered LCD calculators, the Sharp team succeeded in integrating CMOS-LSI ICs and LCD devices onto a single glass substrate. This was termed COS or Crystal On Substrate.
Using this technology, the Sharp Compet EL-805 calculator was launched as the world first battery-powered LCD pocket calculator. This was a breakthrough in the sense that the MOS-LSI and LCD technologies established by this calculator was the starting point for the development of the low-power mobile appliances and personal computers of today.'
Sharp El 5100 Scientific Calculator
The true COS (Crystal on Substrate or Calculator on Substrate) calculator has a circuit board which is made of a glass-like ceramic — see the close-up photographs below. The LCD display is formed directly on this circuit board, which also carries at least two layers of conductive tracks separated by a white, insulating lacquer, and the electronic components. The glass circuit board has no holes in it, all of the components being surface-mount types. The user actually looks through the circuit board when viewing the display.
- View and Download Sharp EL-5100 instruction manual online. SCIENTIFIC CALCULATOR. EL-5100 calculator pdf manual download.
- The EL-510RT performs over 169 scientific and math functions and has a large, easy to read display. It is ideal for students studying general math, pre-algebra, algebra, and trigonometry. Hard cover protects from scratches.
This use of the glass circuit board appears to have been a dead-end in the development of calculators, perhaps because of cost. Subsequent models from Sharp with this type of display have conventional circuit boards, though their LCD display modules have a similar construction to the display section on the glass circuit boards.
Sharp Calculators EL-W535TGBBL 16-Digit Scientific Calculator with WriteView, 4 Line Display, Battery and Solar Hybrid Powered LCD Display, Black & Blue, Black. Sharp EL-5100 S scientific calculator? Its a great calculator and I still use it regularly as an electronics engineer.
All the Sharp models with displays with reflective LCD characters are often referred to as COS models, though this should really only refer to the early examples with the glass circuit boards.
One characteristic of these early DSM (Dynamic Scattering Mode) LCDs with their reflective digits is that they have a hood over the display with a clear window. This allows ambient light coming at the best angle to be reflected of the digits to give optimal viewing of the display. These hoods over the display often take the form of a flip-up display cover which also protects the display when the calculators is not in use.
Sharp calculators with Dynamic Scattering Mode (DSM) Liquid Crystal Displays
Sharp was one of the pioneers of calculators using the DSM (Dynamic Scattering Mode) LCD (Liquid Crystal Display). These DSM LCDs have the now unusual feature of silver-like reflective digits on a dark background, rather than the now common black digits on a light background.
Although Sharp was one of the pioneers of LCD displays, Rockwell is usually credited with producing the first commercial LCD calculators the previous year, 1972, though these required an internal light source and were much larger; see the Lloyds Accumatic 100. However, Rockwell quit LCD calculators after a few models whereas Sharp persisted with the development of LCD displays and later produced many models with the now familiar LCD with black digits.
'COS' technology
Some of these DSM LCD calculators also employ Sharp's 'COS' (Crystal on Substrate) technology. This is a method of manufacture used in the early Sharp LCD calculators where the LCD is formed directly on a glass circuit board substrate (see the close-up photographs below) on which the other electronic components are also mounted. Some subsequent Sharp models with the reflective DSM LCD, although not having the LCD directly formed on the circuit board, are also commonly referred to, incorrectly, as 'COS' models.
The following details of the development of COS and the Sharp EL-805 are based on information kindly supplied by Sharp Corporation:
'A development team headed by Isamu Washozuka had been engaged in developing LCD devices for calculators. Although Rockwell had already produced some large, desktop, AC-powered LCD calculators, the Sharp team succeeded in integrating CMOS-LSI ICs and LCD devices onto a single glass substrate. This was termed COS or Crystal On Substrate.
Using this technology, the Sharp Compet EL-805 calculator was launched as the world first battery-powered LCD pocket calculator. This was a breakthrough in the sense that the MOS-LSI and LCD technologies established by this calculator was the starting point for the development of the low-power mobile appliances and personal computers of today.'
Sharp El 5100 Scientific Calculator
The true COS (Crystal on Substrate or Calculator on Substrate) calculator has a circuit board which is made of a glass-like ceramic — see the close-up photographs below. The LCD display is formed directly on this circuit board, which also carries at least two layers of conductive tracks separated by a white, insulating lacquer, and the electronic components. The glass circuit board has no holes in it, all of the components being surface-mount types. The user actually looks through the circuit board when viewing the display.
- View and Download Sharp EL-5100 instruction manual online. SCIENTIFIC CALCULATOR. EL-5100 calculator pdf manual download.
- The EL-510RT performs over 169 scientific and math functions and has a large, easy to read display. It is ideal for students studying general math, pre-algebra, algebra, and trigonometry. Hard cover protects from scratches.
This use of the glass circuit board appears to have been a dead-end in the development of calculators, perhaps because of cost. Subsequent models from Sharp with this type of display have conventional circuit boards, though their LCD display modules have a similar construction to the display section on the glass circuit boards.
Sharp Calculators EL-W535TGBBL 16-Digit Scientific Calculator with WriteView, 4 Line Display, Battery and Solar Hybrid Powered LCD Display, Black & Blue, Black. Sharp EL-5100 S scientific calculator? Its a great calculator and I still use it regularly as an electronics engineer.
All the Sharp models with displays with reflective LCD characters are often referred to as COS models, though this should really only refer to the early examples with the glass circuit boards.
One characteristic of these early DSM (Dynamic Scattering Mode) LCDs with their reflective digits is that they have a hood over the display with a clear window. This allows ambient light coming at the best angle to be reflected of the digits to give optimal viewing of the display. These hoods over the display often take the form of a flip-up display cover which also protects the display when the calculators is not in use.
Sharp El-5100 Scientific Calculator
The DSM LCD calculators featured on this page are:
