NTSC-J

Key takeaways

NTSC-J belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NTSC-J to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NTSC-J from memory before moving on to harder problems.

Reference excerpt

NTSC-J or "System J" is the informal designation for the analogue television standard used in Japan. The system is based on the US NTSC (NTSC-M) standard with minor differences. While NTSC-M is an official CCIR and FCC standard, NTSC-J or "System J" are a colloquial indicators. The system was introduced by NHK and NTV, with regular color broadcasts starting on 10 September 1960. NTSC-J was replaced by digital broadcasts in 44 of the country's 47 prefectures on 24 July 2011. Analogue broadcasting ended on 31 March 2012 in the three prefectures devastated by the 2011 Tōhoku earthquake and tsunami (Iwate, Miyagi, Fukushima) and the subsequent Fukushima Daiichi nuclear disaster. The term NTSC-J is also informally used to distinguish regions in console video games, which use televisions (see Marketing definition below).

Technical definition

Japan implemented the NTSC standard with slight differences. The black and blanking levels of the NTSC-J signal are identical to each other (both at 0 IRE, similar to the PAL video standard), while in American NTSC the black level is slightly higher (7.5 IRE) than blanking level – because of the way this appears in the waveform, the higher black level is also called pedestal. This small difference doesn't cause any incompatibility problems, but needs to be compensated by a slight change of the TV brightness setting in order to achieve proper images. YIQ color encoding in NTSC-J uses slightly different equations and ranges from regular NTSC. I {\displaystyle I} has a range of 0 to ±334 (±309 on NTSC-M), and Q {\displaystyle Q} has a range of 0 to ±293 (±271 on NTSC-M). YCbCr equations for NTSC-J are C = ( C b − 512 ) ∗ ( 0.545 ) ∗ ( sin ⁡ ω t ) + ( C r − 512 ) ∗ ( 0.769 ) ∗ ( cos ⁡ ω t ) {\displaystyle C=(Cb-512)*(0.545)*(\sin \omega t)+(Cr-512)*(0.769)*(\cos \omega t)} , while on NTSC-M we have C = ( C b − 512 ) ∗ ( 0.504 ) ∗ ( sin ⁡ ω t ) + ( C r − 512 ) ∗ ( 0.711 ) ∗ ( cos ⁡ ω t ) {\displaystyle C=(Cb-512)*(0.504)*(\sin \omega t)+(Cr-512)*(0.711)*(\cos \omega t)} . NTSC-J also uses a white reference (color temperature) of 9300K instead of the usual NTSC-U standard of 6500K. The over-the-air RF frequencies used in Japan do not match those of the US NTSC standard. On VHF the frequency spacing for each channel is 6 MHz as in North America, South America, Caribbean, South Korea, Taiwan, Burma (Myanmar), and the Philippines, except between channels 7 and 8 (which overlap). Channels 1 through 3 are reallocated for the expansion of the Japanese FM band. On UHF frequency spacing for each channel in Japan is the same, but the channel numbers are 1 lower than on the other areas mentioned – for example, channel 13 in Japan is on the same frequency as channel 14. For more information see Television channel frequencies. Channels 13-62 are used for analog and digital TV broadcasting. The encoding of the stereo subcarrier also differs between NTSC-M/MTS and Japanese EIAJ MTS broadcasts.

Marketing definition The term NTSC-J was informally used to distinguish regions in console video games, which use televisions. NTSC-J is used as the name of the video gaming region of Japan (hence the "J"), South East Asia (some countries only), Taiwan, Hong Kong, Macau, Philippines, and South Korea (now NTSC-K) (formerly part of SE Asia with Hong Kong, Taiwan, Japan, etc.). Most games designated as part of this region will not run on hardware designated as part of the NTSC-U, PAL (or PAL-E, "E" stands for Europe) or NTSC-C (for China) mostly due to the regional differences of the PAL (SECAM was also used in the early 1990s) and NTSC standards. Many older video game systems do not allow games from different regions to be played (accomplished by various forms of regional lockout); however more modern consoles either leave protection to the discretion of publishers, such as Microsoft's Xbox 360, or discontinue its use entirely, like Sony's PlayStation 3 (with a few exceptions). China received its own designation due to fears of an influx of illegal copies flooding out of China, which is notorious for its rampant copyright infringements. There is also concern of copyright protection through regional lockout built into the video game systems and games themselves, as the same product can be edited by different publishers from one continent to another.

See also Television in Japan Broadcast television systems ATSC BTSC EIAJ MTS NTSC Clear-Vision PAL SECAM Related topics RCA Oldest television station NTSC-C NTSC-U

References

Illustrations

Worked examples

Example 1 — a first encounter with NTSC-J

Start with the simplest possible case. Write down what NTSC-J claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to NTSC-J before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about NTSC-J ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of NTSC-J

In research: NTSC-J appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses NTSC-J in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: NTSC-J is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1960 introductions, Japanese inventions, Standards of Japan, so understanding it makes those chapters shorter.
In everyday life: Look for NTSC-J outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study NTSC-J in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NTSC-J means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain NTSC-J out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NTSC-J in simple terms?

NTSC-J or "System J" is the informal designation for the analogue television standard used in Japan. The system is based on the US NTSC (NTSC-M) standard with minor differences.

Why does NTSC-J matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study NTSC-J?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on NTSC-J.