New: Ricoh patent application for 21mm f/2.4, 18mm f/2.4, 16mm f/2.4, and 14mm f/2.4 full-frame lenses
Ricoh has a new patent application for multiple full-frame lenses including 21mm f/2.4, 18mm f/2.4, 16mm f/2.4, and 14mm f/2.4:
- Applicant: Ricoh Co., Ltd.
- Publication number: P2022117775
- Application number: P 2021014462
- Publication date: 2022-08-12
- Title of the invention: Single focus lens, interchangeable lens, and imaging device
- Patent description: A single focus lens, an interchangeable lens, and an imaging device that have high optical performance, are compact, lightweight, and have a wide angle of view are provided. Conventional retrofocus optical systems tend to increase in size and cost as the optical performance is improved, due to the increase in the number of lenses and the use of many aspherical surfaces. In addition, the wider the angle of view, the larger the size and the higher the cost. For example, Patent Document 1 has room for improvement in terms of widening the angle of view and correcting off-axis aberrations.
- Summary of the invention: It is an object of the present invention to provide a single focal lens, an interchangeable lens, and an imaging device that have high optical performance, are compact, lightweight, and have a wide angle of view.
Here are some of the lens designs described in the patent:
21mm f/2.4
- Example 1: 21mm F2.4 (already announced)
- Full-frame DSLR lens
- Focal length 21.32
- F number 2.45
- Half angle of view 46.1
- Image height 21.64
- Back focus 40.33
- Total length 115.34
19mm f/2.4
- Example 5: 19mm F2.4
- Focal length 19.36
- F number 2.40
- Half angle of view 49.7
- Image height 21.64
- Back focus 40.84
- Total length 139.25
18mm f2.4
- Example 6: 18mm F2.4
- Focal length 18.51
- F number 2.40
- Half angle of view 50.6
- Image height 21.64
- Back focus 40.44
- Total length 138.85
16mm f/2.4
- Example 7: 16mm f/2.4
- Full-frame DSLR lens
- Focal length 16.45
- F number 2.40
- Half angle of view 54.2
- Image height 21.64
- Back focus 37.89
- Total length 129.54
14mm f/2.4
- Example 9: 14mm F2.4
- Not a DSLR lens (back focus of 20.76mm)
- Focal length 14.04
- F number 2.40
- Half angle of view 58.1
- Image height 21.64
- Back focus 20.76
- Total length 111.15
Via digicame-info
