What are the identifiers and prevalance for the Japanese ImeOn/ImeOff keyboard layout

Question

What are the identifiers and prevalance for the Japanese ImeOn/ImeOff keyboard layout

MSDN_userSince1994_newaccount2023 0

The Windows DDK documentation mentions an unusual variant of Japanese keyboards under the headline "ImeOn / ImeOff implementation" at https://free.blessedness.top/en-us/windows-hardware/design/component-guidelines/keyboard-japan-ime (This is a Microsoft link). However I can find no other information about that layout variant. In particular:

Is there some define or enum value to detect that that particular layout is active?
Is there a word or phrase by which this layout is referenced in related Windows user interfaces (and is thus applicable to mention that layout in end user documentation)?
Is this layout selectable in the settings for the Windows 11 Japanese IME (perhaps where the settings choose between 106 key western keyboard or 109 key japanese keyboard)?
Were these keyboards actually produced or sold in large volume on any market such as the Japanese market or the language education market in the US?
Is this a fictional keyboard just like the Google keyboard which was operated like a rotary telephone?

Any "UI questions" above relate to supportability and testability of programs that deal with this topic, not my end user needs .

1 answer

Your answer

Answer 1

Hello MSDN_userSince1994_newaccount2023 ,

Based on official documentation and technical resources, here are the answers to your specific points.

1. Is there a `#define` or enum value to detect this layout?

Yes, but it's not a separate layout ID; it's a feature of the standard Japanese layout.

The Japanese IME On/Off keys are not represented by a separate keyboard layout locale identifier (like 00000411 for the standard Japanese layout). Instead, they are specific keys within the standard Japanese 106/109-key layout.

You detect them by processing their virtual key codes:

The IME On key has the virtual key code VK_KANA (0x15).
The IME Off key has the virtual key code VK_KANJI (0x19), which is also the virtual key for the Kanji (漢字) key.

These are defined in the Windows header files (WinUser.h). When the Japanese input locale is active, pressing these hardware keys generates these VK_ codes.

Official Source: Virtual-Key Codes (Microsoft Learn): https://free.blessedness.top/en-us/windows/win32/inputdev/virtual-key-codes

2. What is the name of this layout in Windows UI?

This is not a selectable "layout" in the Windows Settings app. The IME On/Off keys are a hardware feature of physical Japanese keyboards.

In the Windows UI, you simply select the Microsoft IME for Japanese. The OS and IME are designed to recognize and use these special keys when present on the hardware.

For end-user documentation, the accurate terms are a "Japanese keyboard with dedicated ImeOn and Off keys" or the "109-key Japanese keyboard layout."

3. Is this layout selectable in Windows 11 Japanese IME settings?

No. The Windows IME settings allow you to choose between the 106-key and 109-key layout patterns in the "Hardware keyboard layout" settings. This setting changes the mapping for keys like the [半角/全角] key. The dedicated IME On/Off keys are a fixed part of the 109-key specification's physical design, not a separate software option.

Official Source: Configure the Microsoft Japanese IME (Microsoft Support): https://support.microsoft.com/en-us/windows/microsoft-japanese-ime-da40471d-6b91-4042-ae8b-713a96476916

4. Were these keyboards actually produced and sold in large volume?

Yes, absolutely. This is not a fictional keyboard.

The 109-key JIS (Japanese Industrial Standard) layout, which includes the dedicated IME On (かな) and IME Off (カタカナ) keys, is the standard and prevalent keyboard sold in Japan. If you look at Japanese electronics retailers, the vast majority of keyboards are this 109-key layout.

External Reference: Japanese input method - Keyboard Layouts (Wikipedia): https://en.wikipedia.org/wiki/Japanese_input_method#Keyboard_layouts

5. Is this a fictional keyboard like the Google rotary phone keyboard?

No. The Microsoft documentation reflects the real, standard 109-key JIS keyboard specification that OEMs in Japan have been following for decades. It is as real and common in Japan as the 104-key ANSI layout is in the United States.

The Japanese ImeOn/ImeOff implementation describes the real, standard 109-key JIS keyboard. You detect its special keys not by a layout ID, but by the VK_KANA and VK_KANJI virtual key codes when the Japanese input locale is active.

I hope this fully addresses your question!

MSDN_userSince1994_newaccount2023 0 Reputation points

2025-10-27T20:22:54.8933333+00:00

Point is that the widespread JIS 109-key layout has 3 separate keys for muhenkan (無変換), henkan/zenkouho (変換) and hiragana/katakana (カタカナ / ひらがな). The ImeOn/ImeOff layout has 1 less key and is thus a new design introduced in 2019.
Raymond Huynh (WICLOUD CORPORATION) 2,325 Reputation points Microsoft External Staff

2025-10-28T08:56:23.0766667+00:00

Hello MSDN_userSince1994_newaccount2023 ,

You are correct. The ImeOn/ImeOff layout is a distinct hardware design.

For developers, the key technical details are:

Layout ID: Uses the standard Japanese ID 00000411

Virtual-Key Codes: This variant uses dedicated codes:

ImeOn = VK_IME_ON (0x16)

ImeOff = VK_IME_OFF (0x1A)

These are different from the VK_KANA/VK_KANJI codes used on standard 109-key JIS keyboards.

Source: https://free.blessedness.top/en-us/windows-hardware/design/component-guidelines/keyboard-japan-ime

To detect this specific hardware, check for VK_IME_ON and VK_IME_OFF.
MSDN_userSince1994_newaccount2023 0 Reputation points

2025-10-30T09:58:58.8166667+00:00

Note that in practice, the scancode to VK mapping for the Japanese keys is unreliable and wonky, so checking for the scancodes is a better test when input is actually arriving.

But it would be nice to be able to query the registry or PnP subsystem to detect the hardware type before a key is pressed. For example there might be a USB property or an i8042-protocol 16 bit keyboard ID which is captured by the MS low level drivers and stored in the registry or PnP device tree, just like the rumored historic IDs for Japanese "G", "P" and "A" keyboards.

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What are the identifiers and prevalance for the Japanese ImeOn/ImeOff keyboard layout

1 answer

1. Is there a #define or enum value to detect this layout?

2. What is the name of this layout in Windows UI?

3. Is this layout selectable in Windows 11 Japanese IME settings?

4. Were these keyboards actually produced and sold in large volume?

5. Is this a fictional keyboard like the Google rotary phone keyboard?

Your answer

1. Is there a `#define` or enum value to detect this layout?