Inkseep Electronic Works

Prismatic

VISUAL SYSTEMS DIVISION
INKSEEP ELECTRONIC WORKS

PICTURE AND DISPLAY ENGINE

A picture with a memory.

Prismatic is a picture and display engine. It takes a picture through tape, reception, decoding, scanning, deflection, the electron beam and the screen, and lets each stage behave as it would, or as it should not.

THE COMMERCIAL

PRISMATIC / 0:58 / SILENT

Silent, 58 seconds.

SIGNAL PATH

Nine figures, from the source to the screen.

Prismatic processes a still or moving picture through models of how a television picture is carried, decoded, scanned and displayed. Each stage has its own controls. The engine keeps the previous picture, so phosphor light, interlaced fields and feedback give motion a visible history. The healthy picture is as much a part of the apparatus as the faulted one.

FIG. 1

Source

  1. Blocks. Squares lose their detail.

  2. Pixel sort. Bright areas drag sideways.

  3. Feedback. Old frames smear into new ones.

Details

Compression artifacts in the material itself, before anything analogue: feedback, block corruption, pixel sorting, hue bands.

  1. Blocks

    Block corruption: squares lose their detail. This damage is in the material itself, before any analogue stage.

  2. Pixel sort

    Bright areas drag sideways into streaks. A threshold sets how bright an area must be.

  3. Feedback

    Datamosh: old frames smear into new ones. The demonstration holds the old picture, then releases it at 4.5 seconds.

Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 3

FIG. 2

Tape

  1. Head drum. Head switching tears the bottom lines.

  2. Dropout. A stretch of tape gives no signal.

  3. Time-base error. Each line starts early or late.

Details

What the transport does to the signal it recovers: flagging, time-base error, head switching, dropouts, mistracking.

  1. Head drum

    The rotating heads read the tape. Head-switch tear displaces the bottom lines of the picture.

  2. Dropout

    A stretch of tape that gives no signal.

  3. Time-base error

    A per-line timing wobble: each line starts a little early or late.

Drawn simplified. Any motion is slowed and illustrative.

FIG. 3

Reception

  1. Direct path. The signal as sent.

  2. Reflected path. Bounced off a building, it arrives later.

  3. Delayed copy. A weaker pulse behind the first: a ghost.

Details

The path to the aerial: multipath ghosts, hum and cross-colour.

  1. Direct path

    The signal as sent.

  2. Reflected path

    The same signal, bounced off a building. It travels farther and arrives later.

  3. Delayed copy

    A weaker second pulse behind the first. On the screen it is a ghost. The engine's ghost delay sets how late it is.

Drawn simplified. Any motion is slowed and illustrative.

FIG. 4

Decode

  1. Luma. 4.2 MHz wide. Carries the edges.

  2. Chroma. About 1.3 MHz wide. Arrives after the edges.

  3. Subcarrier. 3.579545 MHz. Crosstalk into luma is dot crawl.

Details

Channel bandwidth: luma and chroma resolution, chroma lag, and chroma and luma bleeding.

  1. Luma

    The brightness signal, 4.2 MHz wide. It carries the edges.

  2. Chroma

    The color signal, about 1.3 MHz wide, so color is softer than the edges and arrives after them.

  3. Subcarrier

    Color rides on a carrier at 3.579545 MHz. Crosstalk from that carrier into the luma channel is dot crawl.

Bar lengths show bandwidth, not frequency position. The scale is 0 to 4 MHz in 1 MHz steps. Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 2

FIG. 5

Scan

  1. Field one. Every other line.

  2. Field two. Falls between the first field's lines.

  3. Return. The beam goes back to the top.

Details

Two interlaced fields, 59.94 a second, and how much of the last one remains.

  1. Field one

    One field writes every other line of the picture.

  2. Field two

    The second field falls between the first field's lines.

  3. Return

    Between fields the beam goes back to the top.

Each field is 262.5 lines. Two make a frame of 525 lines, at 59.94 fields a second. Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 3

FIG. 6

Deflection

  1. True raster. Straight, square, evenly spaced.

  2. Barrel. Edges bow outward.

  3. Pincushion. Edges pinch inward.

Details

Where on the face the beam lands: barrel, pincushion and corner distortion, drift and supply ripple.

  1. True raster

    Where the lines should fall: straight, square, evenly spaced.

  2. Barrel

    The edges bow outward.

  3. Pincushion

    The edges pinch inward. Corner distortion, drift and supply ripple are further ways the lines miss.

Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 2

FIG. 7

Beam

  1. Guns. Three, named for the colors they light.

  2. Convergence. All three beams cross at one hole.

  3. Mask. Each beam reaches only its own dots.

  4. Triad. Three dots read as one color.

Details

Three guns: where they converge, and what white they make when they do.

  1. Guns

    Three guns, named for the colors their beams light. Electrons have no color.

  2. Convergence

    All three beams cross at one hole in the mask. Where they miss, colors separate.

  3. Mask

    The mask lets each beam reach only its own dots.

  4. Triad

    Three dots, one of each color, read together as one color.

Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 2

FIG. 8

Screen

  1. Stripes. The mask setting for stripes.

  2. Slots. The mask setting for slots.

  3. Dots. The mask setting for dots.

  4. Bloom. Bright light spreads into the dark.

  5. P22 decay. Time to fall to 10%: red 0.76 ms, green 0.12, blue 0.114.

Details

The mask the light passes through and the phosphor behind it: mask type, dot pitch, bloom, wear.

  1. Stripes

    The mask setting for stripes.

  2. Slots

    The mask setting for slots.

  3. Dots

    The mask setting for dots, three to a triad.

  4. Bloom

    Bright light spreads into the dark around it.

  5. P22 decay

    Time for P22 to fall to 10% of its brightness: red 0.76 ms, green 0.12 ms, blue 0.114 ms (the engine's figures, from Kuhn's fits).

The bars are those three measured times only, on a scale of 0 to 0.8 ms in 0.2 ms steps. No curve is drawn between them. Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 1

FIG. 9

Plasma

ALTERNATE TO FIG. 8

  1. Cell. One cell lights one color.

  2. Rows. Electrodes run along the rows.

  3. Columns. Electrodes run down the columns.

Details

An alternate screen structure: a lattice of cells instead of a mask.

  1. Cell

    One cell, lighting one color. The engine draws a lattice of cells in place of the mask.

  2. Rows

    Electrodes run along the rows.

  3. Columns

    Electrodes run down the columns. A cell is selected where a row and a column cross.

Drawn simplified. Any motion is slowed and illustrative.

SHOWN INDEMO 2

DEMONSTRATIONS

One target, four settings.

Each comparison sends one original diagnostic target through four settings of the engine, so only the apparatus changes.

Light that outlasts the source

A bright marker moves, then stops at five seconds. Four phosphors answer it: the warm P22 color tube, P3 amber, P31 green, and P7 with its blue-white flash and long yellow-green afterglow.

DEMONSTRATION 101 / 03

P3 and P31 differ in color here, not in decay speed: the model gives both the same 35 ms minimum picture time constant. Actual output from the engine, six seconds, silent.

The construction of a picture

One alignment target through four paths: a reference color tube; unequal decoded bandwidth, where color arrives after its edges; a deformed raster with separated guns; and a plasma cell structure.

DEMONSTRATION 202 / 03

Settings authored for comparison, not shipped presets. Plasma replaces the tube’s mask; it is not added on top of it. Actual output from the engine, six seconds, silent.

Four answers to motion

The picture changes at three seconds. Retained fields, feedback and small-block corruption each respond differently; feedback is released at four and a half seconds.

DEMONSTRATION 303 / 03

Block corruption is drawn by the engine. It does not damage an encoded file. Actual output from the engine, six seconds, silent.

PARTICULARS

What it is.

Division
Visual Systems Division, Inkseep Electronic Works
Type
Software picture and display engine
Stages
Source, Tape, Reception, Decode, Scan, Deflection, Beam, Screen, Plasma
Phosphors demonstrated
P22 color, P3 amber, P31 green, P7 long-persistence
Picture history
Phosphor persistence, retained interlaced fields and feedback

CREDITS

About the commercial’s footage

Show the credits

Original Inkseep editing, product lettering and manufacturer attribution. Archival images are excerpted, reframed and processed, without their original narration. Historical people, laboratories and factories are not presented as Inkseep employees or facilities. The acquired transfers carry public-domain dedications unless noted.