Memory and Display

Question 1

the memory allows us to store an image but also is responsible for giving us what

Answer 1

a grayscale

Question 2

another name for memory

Answer 2

scan converter

Question 3

analog vs digital (3 things)

Answer 3

A: continuous values (ramp), prone to drift, less reproducible
D: discrete numbers (stairs), stable, reproducible

Question 4

analog scan converter is similar to a CRT except that the phosphor face is replaced with a ______ called a _____

Answer 4

wafer of silicon
dielectric matrix

Question 5

analog scan converter: electrons are emitted by the filament, pass through the ______ plate and strike the silicon wafer leaving a _____ charge

Answer 5

deflection
negative

Question 6

main advantage to analog scan converter vs disadvantage

Answer 6

allows for gray scale
vs
prone to drift and there was no long term memory

Question 7

what do we use instead of an analog scan converter today

Answer 7

we use a digital scan converter

Question 8

what can digital scan converters be connected to and what improved thing do they have

Answer 8

can be connected to many other systems or cameras and have superior resolution

Question 9

DSC: consists of a matrix typically ________(number), which is divided into small rectangular square picture elements called _____

Answer 9

1024x768
pixels

Question 10

each pixel contains a digital number to represent the ______ of the received echo

Answer 10

amplitude

Question 11

a 1024x768 matrix has _____ pixels

Answer 11

786432

Question 12

binary code

Answer 12

computers operate in a binary code, which is a language consisting of only 1s and 0s

Question 13

how do you get several shades of grey using the binary code

Answer 13

You add additional matrices that are stacked on top of the other so that every pixel location can be represented by several 1s and 0s

Question 14

all 256 shades of gray can be represented by ____ stacked matrices

Answer 14

8

Question 15

more pixels = _____ resolution

Answer 15

increased

Question 16

one binary digit

Answer 16

bit - 1 or 0

Question 17

8 bits of data

Answer 17

byte - 10010101

Question 18

bit vs byte

Answer 18

one binary digit vs 8 bits of data

Question 19

word

Answer 19

combination of bits expressed as a unit

Question 20

word length

Answer 20

number of bits in a word

Question 21

bit depth

Answer 21

the word length at each address location

Question 22

RAM

Answer 22

random access memory - fast, rewritable, cheap, erased when machine turned off

Question 23

ROM

Answer 23

read only memory - permanent and used for system function (i.e, pre-sets)

Question 24

the formula for calculating the shades of gray

Answer 24

2^n where n is the bit depth

Question 25

the binary system relies on two digits - 1 or 0 which represents a circuit that is either ____ or ___

Answer 25

on off

Question 26

what is the decimal number

Answer 26

it is where you convert the binary numbers using the chart 128 64 32 16 8 4 2 1 Add up the numbers with a 1 in their space ex. 1001=9

Question 27

why is more pixels in a finite space better

Answer 27

the size of the pixels must decrease to fit the monitor better

Question 28

we also impact the resolution by changing the _____

Answer 28

depth of field

Question 29

axial res = (formula)

Answer 29

1/2 SPL SPL = wavelength x ringdown

Question 30

modern day units use a ____ monitor for display

Answer 30

LCD (liquid crystal display)

Question 31

the _____ was the first to use a CRT and is used in __, __, and ___ mode. It can only display using a x and y axis and is not compatible with a _____ signal

Answer 31

oscilloscope a b m video

Question 32

the television CRT _____ a video signal and is _____ of displaying a wide range of grays

Answer 32

accepts capable

Question 33

if equipped, the CRT is also able to display ____ which is useful for _____ applications

Answer 33

colour Doppler

Question 34

the CRT is a large ____ vacuum tube that contains a cathode or source of _____ (_____).

Answer 34

glass electrons negative

Question 35

the electron beam of a CRT is aimed at ______ (______)

Answer 35

phosphor plate positive

Question 36

______ or _____ deflection plates are used to _____ the beam and the phosphor _____ will depend on the number of electrons that strike it

Answer 36

electrical magnetic steer brightness

Question 37

the number of electrons is dependent on the ___ of the ____ signal

Answer 37

amplitude video

Question 38

to obtain colour there are ____ electron guns that cause phosphor to light up either ____, ___, or _____

Answer 38

three red green blue

Question 39

to move the electron beam a specific method is used called the _____

Answer 39

Raster Format

Question 40

Raster Format: the beam is moved from ____ to ___ and in addition interlacing is used to first write ____ lines and then the ____ lines

Answer 40

left right odd even

Question 41

a complete frame consists of ____ horizontal lines produced at ____ Hz (frame rate)

Answer 41

525 30

Question 42

each frame has two field, the ____ and the ____, produced at ___ Hz (frame rate_

Answer 42

odd even 60

Question 43

raster format is done to help reduce the appearance of ____ to the observer

Answer 43

flicker

Question 44

____ odd lines in 1/60s + _____ even lines in 1/60s = ____ lines every ____

Answer 44

263 262 525 1/30s

Question 45

computer monitors are superior to CRTs in that they have more ____ and ____ and the pixels are _____. This means higher ____

Answer 45

scan lines pixels smaller resolution

Question 46

Where CRTs used ____ lines, monitors use ______ or higher

Answer 46

525 1024 x 768

Question 47

computer monitor lines are written in a _____ manner with frame rates typically higher than ____

Answer 47

progressive 60Hz