CN1617246A

CN1617246A - Method for judging CD

Info

Publication number: CN1617246A
Application number: CN 200310114961
Authority: CN
Inventors: 洪建丰
Original assignee: Lite On IT Corp
Current assignee: Lite On IT Corp
Priority date: 2003-11-13
Filing date: 2003-11-13
Publication date: 2005-05-18
Anticipated expiration: 2023-11-13
Also published as: CN100372015C

Abstract

The present invention provides CD judging method. Laser beam of 650 nm wavelength is used in focusing, the focusing error signal is collected with one light detector and observed for whether to have S curve. In case of no S curve, the laser beam of 780 nm wavelength is then used in focusing, and it is judged whether to have S curve. No S curve represents no CD set inside the CD driver, and having S curve represents some CD set inside the CD driver.

Description

Judge the method for video disc

Technical field

The present invention relates to a kind of method of judging video disc, particularly relate to and a kind ofly judge whether CD-ROM device inserts the method for video disc.

Background technology

CD-RW discsCD-RW has numerous species, such as CD-ROM, CD-R, CD-RW, combined type CD (Hybrid CD), individual layer DVD, DVD-dual layer, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM or the like.Because its information format of different types of CD-RW discsCD-RW and physical characteristics are neither together, CD-ROM device itself must have the different information modes that reads.For example change optical maser wavelength (CD:780nm DVD:650nm), or amplify some specific signal.

Because the progress of science and technology, the consumer needn't buy different CD-ROM device for different types of CD-RW discsCD-RW now.Because occurred supporting the CD-ROM device of the multiple class CD-RW discsCD-RW of access on the market, for example: Combo machine, DVD logging machine.For instance, the Combo machine combines CD-RW and DVD-ROM function, has Duoed the function of access DVD video disc than CD-RW.That is to say that but the Combo machine has the optical maser wavelength of access DVD video disc (optical maser wavelength is 650nm) simultaneously but and the optical maser wavelength of access CD video disc (optical maser wavelength is 780nm).The characteristic of a tractor serves several purposes meets following trend very much.

Yet whether the Combo machine must have video disc to insert step in the Combo machine through a judgement in tray (Tray) inserts, and whether carries out follow-up information with decision and reads.Be illustrated in figure 1 as the step that whether judgement has video disc to insert in the Combo machine.In general, known Combo machine only utilizes optical maser wavelength to do the judgement whether CD-ROM device inserts video disc for the light beam of 650nm.

Step 100: the light beam that with optical maser wavelength is 650nm focuses on action.

Step 110: judged whether that S type curve produces, if execution in step 120 is arranged; Otherwise execution in step 130.

Step 120: video disc subsequent treatment action.

Step 130: finish.

Wherein, the focusing of step 100 action as shown in Figure 2.Laser diode 1 is used for producing laser, and the laser of generation produces a focus point 9 through optical splitter (Beam Splitter) 3 and object lens (Object Len) 5 backs.11 control object lens 5 of focus actuator (Focus Actuator) move up and down, and then change the position of focus point 9.9 dozens of reflected light that produce in CD-RW discsCD-RW 7 backs of focus point are directed at reflected light on the photo-detector 13 through optical splitter 3.The optical signalling that can controlled laser light from the photo-detector 13 focuses on, for example: focus error signal (Focus Error Signal), radio frequency level signal (Rf LevelSignal).

Step 110 is for to judge whether CD-ROM device inserts the key step of CD-RW discsCD-RW, wherein CD-RW discsCD-RW whether insert determined S type curve generation whether.Because the generation of S type curve is exactly to utilize focus point from far near near CD-RW discsCD-RW, collected focus error signal (focusing error signal) record is got up, can form S type curve (S-curve) synoptic diagram as shown in Figure 3.

As shown in Figure 3, when focus point from CD-RW discsCD-RW 38 infinities the time, reflected light is very faint, so its focus error signal is minimum.When focus point moves closer in the CD-RW discsCD-RW 38 each material layer (is example with first reflection horizon 42), the focusing error signal detects folded light beam gradually, and has maximum on the occasion of focusing error FE-PK1 in the positive peak place; And next continuing to shift near first reflection horizon 42 along with focus point, focusing error begins to reduce, and in closing the focus error signal that the focal position obtains zero crossover point 52; Still continue to shift near first reflection horizon 42 with rear focal point, and focus error signal can return null value gradually after through minimal value FE-BT1.So form a S type curve.

That is to say, during through three kinds of material layers (plastic layer 40 surfaces, first reflection horizon 42 and second reflection horizon 44), have S type curve S 0, S1 and S2 respectively and come out at focus point.Therefore can utilize the generation whether S type curve is arranged to judge whether CD-ROM device inserts video disc.If the generation of S type curve is arranged, handle action with regard to execution in step 120 follow-up video discs; If there is not the generation of S type curve, then execution in step 130 finishes.

When in addition, CD-ROM device is inserted video disc; The radio frequency level signal can have maximum crest value when closing focus.Therefore, the radio frequency level signal can be used for also judging whether CD-ROM device inserts video disc.

Yet in the step 100, known optical maser wavelength is the light beam of 650nm when in a single day breaking down, and judges in the above-mentioned Combo machine that the method that whether has video disc to insert will complete failure.Cause the Combo machine can't judge at all and have or not CD-RW discsCD-RW in CD-ROM device, more can't carry out follow-up video disc and read and follow the rail action.Therefore need a more effective method of judging video disc.

Summary of the invention

The purpose of this invention is to provide a kind of method of judging video disc.The present invention is that the light beam with multiple optical maser wavelength in the optical read head focuses on action, reaches more effectively video disc and judges.

The present invention proposes a kind of method of judging video disc, is summarized as follows:

The light beam that with optical maser wavelength is 650nm is carried out an action that focuses on, comprising collect focus error signal on a photo-detector; And whether observation has the generation of S type curve.If the generation of no S type curve is that the light beam of 780nm is carried out the action that focuses on again with optical maser wavelength, and judges whether the generation of S type curve.Wherein do not have the generation of S type curve to represent and do not insert CD-RW discsCD-RW in the CD-ROM device, and the generation of S type curve is represented and inserted CD-RW discsCD-RW in the CD-ROM device.

In order further to understand feature of the present invention and technology contents, consult following about detailed description of the present invention and accompanying drawing, yet accompanying drawing only provide with reference to and the explanation usefulness, be not to be used for the present invention is limited.

Description of drawings

Fig. 1 judges the figure whether step that video disc inserts is arranged in the expression Combo machine;

Fig. 2 is an optical read head focus mechanism action synoptic diagram in the expression CD-ROM device;

Fig. 3 is expression S type curve (S-curve) synoptic diagram; And

Fig. 4 is that the process flow diagram whether CD-ROM device inserts CD-RW discsCD-RW is judged in expression.

The drawing reference numeral explanation:

1 laser diode

3 optical splitters

5 object lens

7 CD-RW discsCD-RW

9 focus points

11 focus actuator

13 photo-detectors

38 CD-RW discsCD-RW

40 plastic layers

42 first reflection horizon

44 second reflection horizon

50 S0, zero crossover point

52 S1, zero crossover point

54 S2, zero crossover point

Step 100: the light beam that with optical maser wavelength is 650nm focuses on action

Step 110: judged whether that S type curve produces

Step 120: video disc subsequent treatment action

Step 130: finish

Step 200: the light beam that with optical maser wavelength is 650nm focuses on action

Step 210: judged whether that S type curve produces

Step 220: video disc subsequent treatment action

Step 230: the light beam that with optical maser wavelength is 780nm focuses on action

Step 240: judged whether that S type curve produces

Step 250: finish.

Embodiment

The present invention utilizes to have two kinds of optical maser wavelengths simultaneously (but but optical maser wavelength of the optical maser wavelength of access DVD video disc and access CD video disc) and these two kinds of optical maser wavelengths is all launched by an optical read head in the Combo machine, improve the known method of only judging video disc with a kind of optical maser wavelength.The present invention additionally re-uses another kind of optical maser wavelength to increase the correctness of judging video disc.

With reference to Fig. 4, Fig. 4 is that presentation graphs is that the present invention judges whether CD-ROM device inserts the process flow diagram of video disc.

Step 200: the light beam that with optical maser wavelength is 650nm focuses on action.

Step 210: judged whether that S type curve produces, if execution in step 220 is arranged; Otherwise execution in step 230.

Step 220: video disc subsequent treatment action.

Step 230: the light beam that with optical maser wavelength is 780nm focuses on action.

Step 240: judged whether that S type curve produces, if execution in step 220 is arranged; Otherwise execution in step 250.

Step 250: finish.

Wherein, optical maser wavelength is that the light beam of 650nm can be in order to access DVD video disc in the step 200.If when in the CD-ROM device CD-RW discsCD-RW being arranged, move up and down the position that changes focus point by optical read head, can collect focus error signal from photo-detector, and form S type curve.

Afterwards, step 210 judges whether the generation of S type curve.If the generation of S type curve is arranged, move with regard to execution in step 220 video disc subsequent treatment; If there is not the generation of S type curve, then execution in step 230 is that the light beam of 780nm focuses on action with optical maser wavelength.Wherein, optical maser wavelength is that the light beam of 780nm can be in order to access CD video disc, and moves up and down to change the position of focus point by optical read head.Step 230 is main with optical maser wavelength be 780nm light beam again duplicate acknowledgment once to increase the correctness of judging video disc; And in optical maser wavelength is the light beam of 650nm when breaking down, and can also utilize optical maser wavelength to judge for the light beam of 780nm whether CD-ROM device inserts video disc.

Same, in step 230, be that the light beam of 780nm focuses on action with optical maser wavelength, if when in the CD-ROM device CD-RW discsCD-RW being arranged, can form S type curve from collected focus error signal on the photo-detector.Step 240 judges whether the generation of S type curve.If the generation of S type curve is arranged, expression optical maser wavelength is that the light beam of 650nm may break down so that can't determine and video disc is arranged, then execution in step 220 video disc subsequent treatment action in the CD-ROM device.If step 240 is judged the generation that does not have S type curve, there is not CD-RW discsCD-RW in the expression CD-ROM device, then execution in step 250 finishes.

The present invention mainly be with optical maser wavelength be 780nm light beam again duplicate acknowledgment once increase to judge the correctness of video disc, and to take precautions against optical maser wavelength be the light beam of 650nm when breaking down, and can also utilize optical maser wavelength to judge for the light beam of 780nm whether CD-ROM device inserts video disc.

In step 200, be that the light beam of 650nm focuses on action with optical maser wavelength, also can utilize optical read head to move the position that changes focus point towards the direction of video disc.In addition in step 230, be that the light beam of 650nm focuses on action with optical maser wavelength, be to utilize optical read head to move the position that changes focus point with direction away from video disc.

In addition, above preferred embodiment and non-limiting S type curve are unique judgment mechanism.When the present invention inserts video disc in CD-ROM device; The radio frequency level signal can have maximum crest value when closing focus.Therefore, the radio frequency level signal can be used for also judging whether CD-ROM device inserts video disc.

Therefore, advantage of the present invention is to propose a kind of correctness of judging the method for video disc in order to increase judgement video disc.

Another advantage of the present invention is to be the light beam of 650nm when breaking down taking precautions against optical maser wavelength, can also utilize optical maser wavelength to judge for the light beam of 780nm whether CD-ROM device inserts video disc.

In sum; though the present invention with preferred embodiment openly as above; yet it is not in order to limit the present invention; any those skilled in the art; without departing from the spirit and scope of the present invention; certainly can be used for a variety of modifications and variations, so protection scope of the present invention should be with being as the criterion of being defined of claims scope of application.

Claims

1. a method of judging video disc comprises the following steps:

Carry out an action that focuses on the light beam of one first optical maser wavelength, and judge according to the generation of a signal specific whether a CD-ROM device inserts a video disc; And, carry out the action of this focusing with the light beam of one second optical maser wavelength if not having this signal specific produces.

2. the method for judgement video disc as claimed in claim 1 is characterized in that: this first optical maser wavelength and this second optical maser wavelength are all launched by an optical read head.

3. the method for judgement video disc as claimed in claim 2 is characterized in that: the action of this focusing is to utilize this optical read head to move the position that changes a focus point, and obtains a focus error signal from a photo-detector.

4. the method for judgement video disc as claimed in claim 3 is characterized in that: when this focus error signal existed at this video disc, this signal specific can be a S type curve.

5. the method for judgement video disc as claimed in claim 1 is characterized in that: this signal specific is a S type curve or a radio frequency level signal.

6. the method for judgement video disc as claimed in claim 1 is characterized in that: after the light beam that comprises this second optical maser wavelength is carried out the action of this focusing, utilize the generation of this signal specific to judge whether this CD-ROM device inserts this video disc.

7. the method for judgement video disc as claimed in claim 1 is characterized in that: the generation of this signal specific is represented this video disc in this CD-ROM device.