# Barcode & QR (バーコードとQRコード)

> Machine-readable graphics printed as stripes and square grids. DENSO WAVE's QR solves orientation with three corner finder patterns — a pattern to be read, inspired by Go boards and halftone screens, now part of the everyday landscape.

- IndexStyle No.435 — https://indexstyle.org/styles/barcode-qr
- Kind: Style · Family: Symbol Systems · Era: 1974 / 1994–
- Mood: Technology, Trust, Play
- Color cues: #e9e6dd / #67635d / #171615 (cues taken from reference works, not a fixed palette)

## Defining characteristics

- Stripes coding by width
- Three corner finder patterns
- Error-correction redundancy
- Pattern made for machines

## Best used for

- Comparing primary sources and canonical works
- Extracting principles that transfer to other media

## Research method

This entry records a historical style; derive the treatment from its sources rather than a fixed recipe:

- Observe the letters, signs and scale of reference works
- Extract the one structure that governs gaze and information
- Verify the materials and behaviors specific to era, region and process

## What to avoid

Don't reduce it to surface signs. Verify the context of era, region, technology and makers.

## Application checklist

Before calling a piece an application of this style, check it against the defining characteristics:

- [ ] Stripes coding by width
- [ ] Three corner finder patterns
- [ ] Error-correction redundancy
- [ ] Pattern made for machines
- [ ] At least one reference work below has been studied directly
- [ ] The caution above ("What to avoid") has been addressed

## Related styles

- **Player Piano Roll (自動ピアノロール)** — The rolled paper medium on which punched holes are the performance itself. The turn from scores read by people to codes read by machines — ancestor of the punch card and the digital sequencer. → https://indexstyle.org/styles/player-piano-roll
- **Pixel Art (ピクセルアート)** — Treats the pixel as an honest unit, building clear form from limited resolution and palette. → https://indexstyle.org/styles/pixel-art

## Further study

- Woodland's circular barcode
- Masahiro Hara's QR development
- designer QR codes, for better or worse

## Reference works

- QRコードの構造（CC BY-SA 3.0） — https://commons.wikimedia.org/wiki/File:QR%20Code%20Structure%20Example%203.svg

## Source of record

- DENSO WAVE — QRコード開発元 — https://www.denso-wave.com/en/

## Machine surfaces

- JSON: https://indexstyle.org/api/styles/barcode-qr
- Image-generation prompt (legally clean): https://indexstyle.org/styles/barcode-qr/prompt.txt
- MCP: https://indexstyle.org/mcp (tools: search_styles, get_style, compose_styles; prompts: image-prompt, apply-style)

## 日本語

縞と正方格子に情報を刷り込む機械可読のグラフィック。デンソーウェーブのQRは切り出しシンボルの三隅で向きを解き、囲碁と新聞の網点に発想を得た「読む模様」を日常の風景にした。

特徴: 縞の太細の符号／三隅の切り出しシンボル／誤り訂正の冗長性／機械のための紋様
注意: 表面的な記号へ還元せず、時代・地域・技術・制作主体の文脈を確認する。