BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical storage medium for recording information using marks and spaces, an optical disc drive for recording, reading, or deleting data on the optical storage medium, an optical storage niedium inspection apparatus for determining whether the optical storage medium is good or defective, and an optical storage medium inspection method for determining whether the optical storage medium is good or defective. 2. Description of the Related Art High density, high capacity optical storage media known as DVD, or Digital Versatile Disc, have been developed as a practical high density, high capacity storage medium, and are today widely used as a data medium for handling video and other such large amounts of information. Development of two-layer optical storage media capable of recording to two data recording layers has also been reported by various manufacturers as a means of achieving optical storage media with even greater storage capacity. Development of means for recording as well as reading large amounts of data is also progressing on many fronts with various approaches being used to achieve increasingly higher recording densities. One such approach is the phase-change optical disc drive using a reversible phase change between crystalline and amorphous states. V, Japanese Patent Laid-ppen Publication No. 2000-200418 teaqlies technology for recording and reading data by emitting a beam to a phase-change optical storage medium. Fig. 20 shows the configuration of a common optical system used in the optical pickup head of an optical recording and playback system as an optical disc drive capable of reading and writing data. The semiconductor laser 1 light source emits a linearly polarized divergent beam 70 with an oscillation wavelength \1 of 405 nm. The divergent beam 70 emitted from semiconductor laser 1 is converted to parallel light by a collimating lens 53 with a 15 mm focal length, and is then incident to a diffraction grating 58. The divergent beam 70 incident to the diffraction grating 58 is split into three beams of orders 0 and +/-1 diffracted light. The order 0 diffracted light is the main begm 70a for data recording and playback, and the order +/-1 diffracted beams are the two sub-beams 70b and 70c used when detecting the trade recorded after recording to one adjacent track. Furthermore, the track having a specified playback signal quality can be recorded after recording to both adjacent tracks. Furthermore, the track having a specified playback signal quality can be recorded multiple times. Further preferably, playback signal quality is the same specified level in all of a specific number of recordings. The optical disc drive could record at a second emission power level after recording at a first emission power level, the first emission power level being higher than the second emission power level. An optical disc drive according to the present invention determines the emission power for recording according to the detected playback signal quality. Further preferably, the emission power is determined in an area outside the user area for recording user data. With the configuration of an optical storage medium inspection apparatus according to the present invention described above jitter not including jitter relating to marks and spaces of the shortest recordable length is measured and used to determine whether the optical storage medium is good or defective. More specifically, two threshold values are used to identify the shortest marks. When using a two-layer optical storage medium to which data is recorded with the same recording density on two data recording surfaces, this reduces the effect of increased jitter resulting from marks on the recording layer closer to the optical pickup head being smaller than the desired size, and enables a reliable good/defective determination. The effect of degraded jitter resulting from the shortest marks and spaces can likewise be reduced when applied to an optical disc drive, and data can be reproduced with high reliability from two data recording layers. Data can also be recorded and reproduced with high reliability using an optical storage medium on which jitter from the shortest marks and spaces is worse than jitter from longer marks and spaces. ' BRIEF DESCRIPTION OF THE DRAWINGS The objects, features, and benefits of the present invention will be known from the preferred embodiments of the invention described below in conjunction with the accompanying drawings: Fig. 1 is a schematic drawing of the configuration of an optical disc drive according to a first embodiment of the present invention; Fig, 2 shows the configuration of the signal processing part of an optical disc drive according to a first embodiment of the present invention; Fig. 3 shows an RF signal obtained by an optical disc drive according to a first embodiment of the present invention; Fig. 4 shows the relationship between a clock signal and marks on an optical storage medium in an optical disc drive according to a first embodiment of the present invention; Fig. 5 shows the relationship between signal amplitude and mark length on an optical storage medium in an optical disc drive according to a first embodiment of the present invention; Fig. 6 shows recording pulses in an optical disc drive according to a first embodiment of the present invention; Fig. 7 shows the configuration of an optical storage medium according to a second embodirnent of the present invention; Fig. 8 shows the configuration of the signal processing part of an optical disc drive according to a third embodiment of the present invention; Fig. 9 is a block diagram of an optical disc drive according to a fourth embodiment of the present invention; Fig. 10 shows the track configuration of an optical storage medium in a fourth embodiment of the present invention; Fig. 11 shows the correlation between peak power and Jitter in a fourth embodiment of the present invention; Fig. 12 is a flow, chart related to a fourth embodiment of the present invention; Fig. 13 is a flow chart related to a fourth embodiment of the present invention; Fig. 14 is a block diagram of an optical disc drive according to a fourth embodiment of the present invention; Fig. 15 is a block diagram of an optical disc drive according to a fourth embodiment of the present invention; Fig. 16 is a block diagram of an optical disc drive according to a fourth embodiment of the present invention; Fig. 17 is a block diagram of an optical disc drive according to a fourth embodiment of the present invention; Fig. 18 describes the output signal of an optical disc drive according to a fourth embodiment of the present invention; Fig. 19 describes the output signal of an optical disc drive according to a fourth embodiment of the present invention; Fig. 20 is a schematic diagram of an optical pid<:up hea?| in an optical disc drive according to the related art; Fig. 21 shows the relationship between the beam and tracks on the optical storage medium in a conventional optical disc drive; Fig. 22 shows the relationship between the beam and photodetector of the optical pickup head in a conventional optical disc drive; Fig. 23 shows an RF signal obtained by a conventional optical disc drive; Fig. 24 is a block diagram of a conventional optical disc drive; Fig. 25 shows the track configuration of a conventional optical storage medium; Fig. 26 shows the relationship between peak power and jitter in a conventional optical disc drive; and Fig. 27 is a flow chart relating to a conventional optical disc drive. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an optical disc drive according the present invention are described below with reference to the accompanying figures. It should be noted that like reference numerals in the accompanying figures denote identical elements or elements effecting the same action or operation. Embodiment 1 Fig. 1 shows an example of the configuration of an optical disc drive according to a first embodiment of the present invention. This optical disc drive has an optical pickup head 80, optical disc drive unit 81, optical pickup head drive unit 82, signal processing unit 83, and power supply unit 84. A configuration having a power supply unit 84 is shown in the figure, but a configuration in which a connection terminal (not shown) to en external power supply (not shown) is provided instead of power supply unit 84 and ppvyer is supplied by connecting the external power supply and connection terminal could be used. Furthermore, the configuration of the optical pickup head 80 is in no way limited, and the optical picl 1) (c) If the first detection result returned by the playback signal quality detection means A 104 is OK and the second detection result is NG, the optimal recording power determining means 106 uses the follov»(ing equation to calculate power P2, which is the average power {P1) of the first peak power setting and the second peak power setting plus a specific margin (step 411). PI = (current peak power + previous peak power)/2 P2 = K1 X PI (adding a margin, where K1 > 1) (d) If the first detection result returned by the playback signal quality detection means A 104 is OK and the second detection result is OK, peak power is set to a level lower than the peak power used for the second recording, recording is repeated at this peak power setting and playback signal quality is detected. If the third detection result from the playback signal quality detection means A 104 is NG, the optimal recording power determining means 106 calculates power P2 as the average (PI) of the second peak power and third peak power settings plus a specific margin (step 411). (e) This peak power P2 is then set (step 412) and a random signal is recorded and reproduced using peak power P2 (step 413). (f) The playback signal quality detection means A 104 then detects playback signal quality (step 414). (g) If the detection result Is NG, the margin coefficient K1 used in step 411 is changed (step 415), and the process repeats from step 412. If this changed margin coefficient results in an OK detection result, playback signal quality is next detected by playback signal quality detection means B 105 (step 416). If the detection result is NG, the margin coefficient K1 used in step 411 is changed (step 417), and the process repeats from step 412. If playback signal quality is OK as a result of this changed coefficient, peak power P2 is used as the peak power for recording user data (step 418). The change to coefficient K1 in step415 is a maximum +/-1p%, and in step417 is 9 maximum +/-5%. By detecting jitter from the edges of the shortest marks and spaces and detecting jitter not including from the edges of the shortest marks and spaces in order to confirm recording performance, data can be correctly recorded even when defocusing or relative tilt between the head and optical storage medium occurs during actual recording. Furthermore, even better-optimized recording and playback is possible by setting a threshold value for jitter including the edges of the shortest marks and spaces and a threshold value for jitter not including the edges of the shortest marks and spaces. In other words, even better-optimized recording and playback is enabled v^^en the optical storage medium can record so as to satisfy the threshold value for jitter including the edges of the shortest marks and spaces and the threshold value for jitter not including the edges of the shortest marks and spaces. It should be noted that these threshold values could be recorded to a read-only area of the optical storage medium, or they could be stored in memory in the optical disc drive. It will also be obvious that the preceding embodiments are described by way of example only, and the present invention can be varied in many ways without departing from the scope of the invention. For example, leading and trailing mari< edges are not distinguished for use as a jitter and error rate evaluation standards, but they could be. By identifying the leading edges and trailing edges, cases in which jitter or the error rate is particulariy high at either the leading or trailing edge can be eliminated. Furthermore, if edges not including the shortest marks and spaces can be identified, the error rate cpuld be used instead of jitter as the deftected value. Furthermore, edges including the shortest marks and spaces are detected by measuring the pulse intervals in the output signal 111 of the digitizing circuit 604, but detecting the shortest marks and spaces shall not be limited to this method. More specifically, the detection method is not specifically limited, and a method in v\4iich two threshold values SL1 and SL2 are set as shown in Fig. 3 and the shortest marks and spaces are detected from signal amplitude could be used, Furthermore, the edge interval measuring circuit 906 does not measure edge intervals masked by the output signal 902 of selector circuit 901, but another method could be used insofar as it can measure jitter from edges not including the shortest marks and spaces. Furthermore, edge intervals are measured based on the output signal 111 of digitizing circuit 604 and the output signal 112 of PLL 605, but edge interval measurement shall not be so limited and the edge interval could be measured for only CHJtput signal 111 of 504. If jitter in output signal 112 can be ignored, jitter in the edge intervals of the digitizing circuit 604 output signal 111 is logically approximately 1.41 times edge interval jitter based on digitizing circuit 604 output signal 111 and PLL 605 output signal 112, and adequate benefit is achieved by detecting only jitter in the edge intervals in the output signal 111 of digitizing circuit 604. Using PRML in the playback system further improves shortest mark and shortest space detection performance. In this case detecting jitter from edges not including the shortest marks and spaces Is particularly effective in the present embodiment. For example, when two recording stateis having equal jitter at all edges are cprnpared, a lower jitter level from edges not including the shortest marks and spaces means that data can be reproduced more accurately. However, because of the effect of the shortest marks and spaces, edges including the shortest marks and spaces can be correctly detected as 2T marks and spaces using a PRML method even when jitter is high at all edges. As a result, data can be reproduced more accurately than when jitter from all edges is low. Furthermore, the coding system shall not be limited to a shortest mark length of 2T, and the same effect can be achieved whether the shortest mark length is 3T, 1T, or other length. By recording martcs so as to minimize variation in edges not including the shortest marks and spaces, data can be correctly reproduced when a PRML method is used even if jitter for all edges is high if the marks are recorded with sufficient amplitude to enable detecting whether or not a signal is present even when the shortest marks and spaces are not recorded at the connect time interval. As a result, detemnining the recording conditions by detecting jitter for edges not including the shortest marks and spaces as in the present embodiment is therefore extremely effective. Furthermore, this embodiment detects both jitter from edges not including the shortest marks and spaces and jitter from edges including the shortest marks and spaces, but adequate performance is achieved even when only jitter for edges not including the shortest marks and spaces is detected. Yet further, adequate performance is achieved whether jitter is detected for edges not including the shortest marks and spaces, or whether jitter is detected only for edges not including the shortest marks or for edges not including the shprteist spaces, Furthermore, even if a PRML method is not used, the shortest mark length is known in the case of RLL coding, and the shortest marks and spaces can be easily detected. More specifically, if RLL(1,7) modulation is used and a 2.5T signal is detected from the playback wavefonti, the signal could be a 2T or 3T signal, but a 2T signal is likely if a signal shorter than 2T is detected. Detecting jitter from edges not including the shortest marks and spaces as described in the present embodiment is therefore effective when RLL coding is used for recording. The jitter level used as the threshold value will vary according to the enror correction capability of the optical disc drive and the type of equalizer. Assuming an optical disc drive with a bit error rate of 1.0 x 10-4 to 1.0 x 10-3 before error correction, however, a level of approximately 8% to 11% is preferable in playback signal quality detection means A 104 using a nonnal linear equalizer as used in this embodiment of the invention, and a level of approximately 6% to 9% is preferable using a nonlinear equalizer, such as a limit equalizer in which signal boost is greater than in a linear equalizer. Likewise in playback signal quality detection means B 105, 7% to 10% is preferable with a normal linear equalizer as in the present embodiment, and 5% to 8% is preferable with a nonlinear equalizer, such as a limit equalizer in which signal boost is greater than in a linear equalizer. The jitter level used for the threshold value in playback signal quality detection means A 104 is greater than or equal to the jitter level used as the threshold value In playback signal quality detection means B 106. The jitter level can vary 1-2% according to the configuration of the playback channel. The period for continuous recording and continuous playback shall also not be limited, and. recording by either sector unit or ECC block could be used in an optical disc drive that records by sector unit. Test recording shall also not be limited to one revolution of the recording track. Five tradack signal quality denoted by a signal not including edges adjacent to the shortest marks and/or the shortest spaces, and a second playback signal quality denoted by a signal including edges adjacent to the shortest marks and/or the shortest spaces. A forty-seventh version of the invention is an optical disc drive for recording so that a signal not including edges adjacent to the shortest marks and/or the shortest spaces has a first playback signal quality, the optical disc drive characterized by comprising means for recording a signal, means for reproducing the recorded signal, means for detecting a shortest mark or a shortest space in the reproduced signal, and a playback signal quality detection means for detecting playback signal quality in a signal not including edges adjacent to the detected shortest mark or shortest space. A forty-eighth version of the invention is an optical disc drive wtierein a signal including edges adjacent to the shortest marks and/or the shortest spaces denotes a second playback signal quality. A forty-ninth version of the invention is an optical disc drive wherein the first playback signal quality is higher than the second playback signal quality. A fiftieth version of the invention is an optical disc drive that detects jitter as playback signal quality. A fifty-first version of the invention is an optical disc drive that distinguishes leading-edge jitter and trailing-edge jitter. A fifty-second version of the invention is an optical disc drive that detects an error rate as playback signal quality, A fifty-third version of the invention is an optical disc drive that sets playback signal quality for each recording layer of an optical storage medium having multiple recording layers. A fifty-fourth version of the invention is an optical disc drive wherein the quality of the layer farthest from the optical pickup head during recording is highest. A fifty-fourth version of the invention is an optical disc drive wherein the pla^ack signal quality threshold value Is written to a specific area of the optical disc drive. A fifty-fifth version of the invention is an optical disc drive wherein signals are also recorded to tracks adjacent to a track having a specified playback signal quality. A fifty-sixth version of the invention is an optical disc drive wherein the track having a specified playback signal quality is recorded before recording to the adjacent tracks. A fifty-seventh version of the invention is an optical disc drive wherein the emission power of the laser beam when recording the adjacent tracks is greater than the emission power of the laser beam when recording the track having a specified playback signal quality. A fifty-eighth version of the invention is an optical disc drive wherein the track having a specified playback, signal quality is recorded after recording to one adjacent track. A fifty-ninth version of the invention is an optical disc drive wherein the track having a specified playback signal quality is recorded after recording to both adjacent tracks. A sixtieth version of the invention is an optical disc drive wherein the track having a specified playback signal quality is recorded multiple times. A sixty-first version of the invention is an optical disc drive having a specified playback signal quality in all of a specific number of recordings. A sixty-second version of the invention is an optical disc drive characterized by recording at a second emission power level after recording at a first emission power level, the first emission power level being higher than ihe second emission power level. A sixty-third version of the invention is an optical disc drive characterized by determining emission power for recording according to the detected playback signal quality. A sixty-fourth version of the invention is an optical disc drive wherein the emission power is determined in an area outside the user area for recording user data. Although the present invention has been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications afe to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom. WE CLAIM: 1. An optical storage medium which is determined from measured jitter if the optical storage medium is good or defective, the medium including a recordmg layer to which digital information is recorded as a train of marks or spaces of length kT based on a period T and an interger k, wherein the jitter is measured from the marks or spaces except for shortest marks or spaces of the optical storage medium. 2. An apparatus for at least one of reproducing information from the optical storage medium and recording information to the according to claim 1. 3. An optical storage medium including multiple tracks formed concentrically or in a spiral, for recording information using marks and spaces between the marks, each mark having a mark length limited by run length limited (RLL) modulation, wherein a signal not including edges adjacent to the shortest marks and/or the shortest spaces denotes a first playback signal quality. 4. Fabricating method for fabricating the optical disc medium as claimed in claim 3, or computer program for executing the method, or an apparatus for executing method.