Integration of mono-space font and proportional font

IPAex Mincho, the integration of IPA Mincho and IPA P Mincho, and IPAex Gothic, the integration of IPA Gothic and IPA P Gothic are newly developed. This new font series is strictly following Japanese printing font tradition, namely, Japanese characters (Kanji, Kana and punctuation marks) are full width mono-space pitch, and Western characters are proportional pitch.

Some characters are redesigned to improve total readability

IPAex fonts have been redesigned, with continuity from IPA font, as follows:

(1) Hiragana design of IPAex mincho and Katakana voiced sound mark (Japanese diacritical mark) design of IPAex Gothic have been fully reviewed and refined.

(2) The design of mathematical symbols has been totally adjusted and harmonized.

(3) Some of western characters, which were originally designed full width pitch have been redesigned proportionally.

(4) The design of allows, geometrical patterns, and other symbols has been optimized to full width.

(5) The glyph of U+0361(COMBINING DOUBLE INVERTED BREVE) and U+203F (UNDERTIE) have been changed because these two characters had different pitch from usual Japanese printing fonts.

Glyph assignment change of a couple of character codes (Japanese currency marks and back slash)

For IPA fonts Japanese currency mark(\) has been assigned doubly to U+005C and U+00A5. However, for IPAex fonts Japanese currency mark(\) has been assigned to U+00A5 and back slash(\) has been assigned to U+005C, to guarantee international consistency and interchangeability.

JIS X 0203:2000 based designs of glyphs are included using IVS functionality

IPAex fonts include both of JIS X 0213:2000 shapes and JIS X 0213:2004 shapes, which are different from each other, using IVS (Ideographic Variation Sequence) functionality (see note[1]). The number of these characters is 171.

Newly implemented frequently used symbols

Frequently used symbols in Unicode CJK Symbols, CJK Compatibility Symbols and Enclosed CJK, namely symbols included in AJ1-6, have been newly designed and implemented. 202 symbols have been added.

Addition of hinting information (Every IPA font including IPAex fonts)

Hinting information has been added to improve the visibility of small pixel number size characters. Hinting information is very useful to improve the quality with reforming the squashed small characters and unequal thin lines when outline fonts are rendered with small display.

Fully conformed with OpenType Font Specification (Every IPA font including IPAex fonts)

IPA fonts is now fully conformed with OpenType Font Specification (see [2]), to guarantee interoperability among multiple platforms as public fonts.
The improved issues are as follows:

(1) Change of em unit
em unit has been changed from 1,000 of IPA font series to 2,048, conforming OpenType (TrueType) specification. em unit is relative unit to describe glyph size and coordinate when font is developed. According OpenType Font Specification, em unit should be power of 2 and ideally 2,048 is the best(see [3]).

(2) Addition of top four characters in the code table
Top four characters have been changed to .notdef, .null, CR and space to conform to OpenType (TrueType) specification (see [4]).

Addition of information about combining of Hiragana or Katakana plus U+3099(COMBINING KATAKANA-HIRAGANA VOICED SOUND MARK) or U+309a(COMBINING KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK)

Glyph design change of half-em western characters of IPA Gothic

To improve distinguishability between Western characters and numeric characters for mainly programing use and data representation.
target:
U+002c：comma   ,
U+0030：numeral zero  0
U+003b：semicolon  ;
U+0044：western alphabet D
U+0049：western alphabet I
U+006c：western alphabet l

Bug fix (IPA Mincho, IPA P Mincho, IPA Gothic and IPA P Gothic)

(1) Western alphabet characters were proceeded with full width pitch in desktops of some of Linux distributions.
Post table header “isFixedPitch” flag is changed to “0”.

(2) Change of file name extension from .otf to .ttf
IPA fonts (ver.003.xx) and IPAex Fonts are fully conformed with OpenType Specification (see [5]) in general, and the method to describe font outline curve is conformed with TrueType Specification, so IPA font series is conferment with “TrueType Outline based OpenType Specification”. So, IPA font used “.otf” extension for their font names. However, some Operating Systems can not distinguish and accept such “TrueType Outline based OpenType Specification” with “.otf” extension. To easily solve this issue, the file name extensions have been changed from “.otf” to “.ttf”. This change usually does not make negative effect to other environments.

• In the Readme file included in the download files of IPA Fonts Ver.003.02 released from this site, the file name extension was shown as “.otf”, while it should be “.ttf”. The fixed version has been on the site since March 16, 2010, 11:30am. We apologize for the inconvenience this caused.

Note:
[1] Ideographic Variation Sequence (IVS):
Standard procedure to distinguish glyph variation of Ideographs with common Character code (see http://unicode.org/reports/tr37/).
[2] OpenType Font Specification:
http://www.microsoft.com/typography/otspec/
[3] Hinting and production guidelines specification:
http://www.microsoft.com/typography/developers/delivery/hinting.htm
[4] Top four characters of Glyph IDs:
http://www.microsoft.com/typography/otspec/recom.htm
[5] Open Type Font:
Improved from TrueType Font Specification. Adobe and Microsoft have co-developed and are maintaining with approval from Apple. This specification is freely available and the de facto standard among Linux, Windows and Mac OS X, as a cross platform specification.