LCD projector

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Quick Questions

Shade in the A or B circle for each question.

1. Which part of an LCD projector makes the image that is shown on the screen?

A A laser that draws the picture on the screen

B Small LCD panels that the light passes through

2. What is the light source in an LCD projector?

A A bright lamp

B Millions of tiny moving mirrors

3. How many LCD panels does an LCD projector use to build a colour image?

A Three: one each for red, green and blue

B One panel for all the colours at once

4. What happens to the red, green and blue light after it passes through the LCD panels?

A Each colour is sent to a separate screen

B It is recombined into one image

5. What is the job of the lens in an LCD projector?

A To focus the light onto the screen

B To produce the light for the image

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1LCD projector		Alamp -> RGB LCD panels -> recombine -> lens -> screen
2Red, green and blue LCD panels		BAn output device that shines a bright lamp through small LCD panels to make an image, then focuses it onto a screen with a lens
3The light is recombined and a lens focuses it so the picture is sharp on the screen		CLCD panels do not make their own light. An LCD projector needs a bright lamp (light source) to shine light through the panels.
4An LCD projector is often used in a classroom so a teacher can show slides to a whole class		Doutput_device = "LCD projector"; use = "classroom"
5LCD projector: no lamp needed, the LCD panels make their own light		EThe red, green and blue LCD panels form the colour parts of the image. The lens focuses the recombined light onto the screen. It does not split it.
6LCD projector: a lens splits the light into red, green and blue		FThree small panels that each let through only some of the lamp's light to form one colour part of the image

Definitions

LCD projector

Fill in the Blanks

Complete each line of code by filling in the missing parts.

An LCD projector is an ______ device

A bright ____ is the light source

LCD panels: red, green and ____

A ____ focuses the light onto a screen

Used in classrooms and _______

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A lamp.switch_on()

B light = lamp.shine()

C image = mirrors.filter(light)

D lens.focus(image)

Question 2

A lamp = bright_light()

B panels = [red, yellow, blue]

C light = recombine(panels)

D lens.focus(light, screen)

Question 3

A lamp = dim_light()

B panels = [red, green, blue]

C image = form(lamp, panels)

Question 4

A projector = LCDProjector()

B projector.connect(laptop)

C projector.lamp.focus(screen)

D projector.show(slides)

Question 5

A light = lamp.shine()

B image = panels.form(light)

C beam = split(image)

D lens.focus(beam, screen)

Answer Key

LCD projector

Section A: Quick Questions

B — Small LCD panels that the light passes through

A — A bright lamp

A — Three: one each for red, green and blue

B — It is recombined into one image

A — To focus the light onto the screen

Section B: Match the Pairs

LCD projector → An output device that shines a bright lamp through small LCD panels to make an image, then focuses it onto a screen with a lens

Red, green and blue LCD panels → Three small panels that each let through only some of the lamp's light to form one colour part of the image

The light is recombined and a lens focuses it so the picture is sharp on the screen → lamp -> RGB LCD panels -> recombine -> lens -> screen

An LCD projector is often used in a classroom so a teacher can show slides to a whole class → output_device = "LCD projector"; use = "classroom"

LCD projector: no lamp needed, the LCD panels make their own light → LCD panels do not make their own light. An LCD projector needs a bright lamp (light source) to shine light through the panels.

LCD projector: a lens splits the light into red, green and blue → The red, green and blue LCD panels form the colour parts of the image. The lens focuses the recombined light onto the screen. It does not split it.

Section C: Definitions

LCD projector — An output device: a bright lamp shines light through red, green and blue LCD panels that form the image, then a lens focuses the recombined light onto a screen.

Section D: Fill in the Blanks

An LCD projector is an output device

A bright lamp is the light source

LCD panels: red, green and blue

A lens focuses the light onto a screen

Used in classrooms and offices

Section E: Spot the Error

C — An LCD projector makes the image with LCD panels, not mirrors (mirrors are used in a DLP projector). It should be image = panels.filter(light).

B — The LCD panels are for red, green and blue light. Yellow is not one of the three panels. It should be [red, green, blue].

A — An LCD projector needs a bright lamp so the image can be seen on a screen in a lit room. It should be lamp = bright_light().

C — The lens focuses the light onto the screen. The lamp only produces the bright light. It should be projector.lens.focus(screen).

C — After the red, green and blue panels form the image, the light is recombined into one beam, not split again. It should be beam = recombine(image).