1、SMPTE STANDARD for Television Analog Recording - %-in Type E- Small Video Cassette SMPTE 31 M-2003 Revision of ANSVSMPTE 31M-1995 Page 1 of 6 pages 1 Scope This standard specifies the dimensions of a video cassette for use with a 3/4-in type E helical-scan video tape recording cassette system, opera
2、ting at a tape speed of 95.3 mm/s (3.75 ink). 2 Dimensions 2.1 The dimensions necessary for the interface of equipment shall be as specified in the figures and table. 2.2 The metric dimensions are primary. 3 Datum planes 3.1 Datum plane A is the plane determined by spots A, B, and C in figure 5. 3.2
3、 Datum plane B is the plane that includes the center of datum holes (a) and (b) and is orthogonal to datum plane A. Datum holes (a) and (b) are specified in figure 2. 3.3 Datum plane C includes datum hole (a) and is orthogonal to both datum planes A and B. 4 Measurement environment The temperature s
4、hall be 20C i 1 “C (68F * 2F) with a relative humidity of (50 * 2)%. Table 1 - Dimensional tolerances not otherwise specified Millimeters Inches Over To Tolerances Over To Tolerances 0.0 4.0 f 0.2 0.000 0.157 f 0.008 4.0 16.0 f 0.3 0.157 0.630 * 0.012 16.0 63.0 f 0.4 0.630 2.480 f 0.016 63.0 250.0 r
5、t 0.5 2.480 9.843 0.020 Copyright Q2003 by THE SOCIEN OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved February 7,2003 SMPTE 31 M-2003 4 -I- Datum Plane C (See Figure 2) F Unit : mm ) , Datum Plane A Pull.Out Reces 7 i111 i- 120.8 Plane
6、 A 148 IO“:$ 121.4 r- - NOTES 1 Hatched area shows the label area and/or window area. 2 Guide groove. 3 Holding groove. 4 The outer edges should be slanted, but not more than 5“ from vertical. 5 An adaptor recess should be on both sides. 6 These dimensions are inspected by using limit gauges. 7 The
7、dimension shall be specified from datum plane A (see figure 5). Figure 1 - Top view of video cassette Page 2 of 6 pages SMPTE 31 M-2003 Unit : rnm - Section C-C Not. 8 L- NOTES 1 Recording is possible when the hole is covered. 2 The cap must not protrude from datum plane A. 3 Datum hole (a) is prima
8、ry. 4 Tape holder. 5 These dimensions are specified from datum plane A (see figure 5). 6 The tape guide of supply side specified in the figure may also be used. 1 Safety cap Note 2 Section D-D - Figure 2 - Bottom view of video cassette Page 3 of 6 pages SMPTE 31 M-2003 Unit : rnrn 15.5 DIA hQIoi -7-
9、 or O h ID i_1 t Lockingwindow View in dimion of arm X Now 6 I I Note 4 A lPiO.6 Section A-A Note 2 - NOTES 1 The protecting lid of the cassette shall open (height H) more than 35 mm (1.38 in). Height H is measured from datum plane A. Recorder/player unit shall be designed to open the protecting lid
10、 (height H) between 30 mm and 35 mm (1.18 in and 1.38 in) during operation. 2 The protecting lid opens as shown in section A-A when the cassette is inserted into the recorder/player. Maximum force to open the lid shall be 0.981 N (100 gf). 3 Section B-B shows the relationship between the cassette an
11、d the unlocking level of the recorder/player. 4 The arrow shows the direction of cassette insertion. 5 Hole for drive pin. 6 The supply and take-up reels are of two types: Hub diameter (D) of type I reels: 38 mm (1.50 in) Hub diameter (D) of type II reels: 59 rnm (2.32 in) 7 Distance when the lid is
12、 locked. 8 Suggested design. Figure 3 - Location of reels and protecting lid Page 4 of 6 pages SMPTE 31 M-2003 Unit : mm Note 1 I I Note 2 O0 + ln a O z 0 4- - Datum PianeA + Supply reel spindle 2 Take-up reel spindle UJ m O c z 34 DIA Pins at trisected points on FI10 circle Note 3 30.9 DIA YI (4 DI
13、A) Plane e I UJ Reel retaining surface NOTES 1 Center of tape on supply reel when cassette is inserted in recordedplayer. 2 Center of tape on take-up reel when cassette is inserted in recorder/player. 3 Pins of the reel spindle drive the reel and can be pressed down to the level of plane B. 4 Distan
14、ce between centers of two reel spindles. 5 Distance between reel retaining surface of supply reel and datum plane A of cassette when cassette is inserted in 6 Distance between reel retaining surface of take-up reel and datum plane A of the cassette when cassette is inserted in Figure 4 - Relationshi
15、p between reels and spindles recorder/player. recorder/player. Page 5 of 6 pages SMPTE 31M-2003 Datum Plane A Note 1 Datum Plane C Supporting areas Note 2 110f0.2 c Plane - 114 4 10 - NOTES 1 Datum plane A is determined by datum spots A, B, and C. 2 Datum spot D shall be coplanar within 0.2 mm (0.008 in) of data plane A. 3 Flatness of the hatched area shall be coplanar within 0.5 mm (0.020 in) of datum plane A. Figure 5 - Flatness of bottom surface of cassette Annex A (informative) Bibliography ANSIISMPTE 21 M-1997, Video Recording - 3/44 Type E Helical-Scan - Records Page 6 of 6 pages
