JPH06162754A - Optical disk subsystem - Google Patents

Abstract

PURPOSE:To easily use an optical disk device even in a host machine which is not provided with an SCSI connection and is provided with only a CPU bus connector and to minimize the reduction of a space factor at a low cost. CONSTITUTION:When the optical disk device on the market which is provided with an SCSI connector, is used in the host machine provided with only a CPU bus connector 1c like a note type personal computer 1, it is necessary to prepare an independently obtained extension box between them. In this optical disk subsystem 3, an optical disk unit 4 provided with an SCSI connector 4s, a converter 5 for mutual conversion between a CPU bus signal and an SCSI signal, and a CPU bus connector 6 are stored in one casing. Thus, the optical disk device can be connected to the note type personal computer 1 with one CPU bus cable 8. Consequently, the optical disk device is used more easily and is less bulky and has a lower cost in comparison with preparation of the extension box.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk subsystem used by connecting to a host machine equipped with a CPU bus connector.

[0002]

2. Description of the Related Art Recently, the interface between a personal computer (hereinafter referred to as "personal computer"), a word processor (document creating device), and its peripheral devices is SCSI.
Those that conform to the standard are becoming common, and almost all large-capacity external storage devices such as hard disk devices and optical disk devices are equipped with a SCSI interface and its connector.

However, even if an old personal computer that has already been on the market or a personal computer that is currently on the market, the SCSI
Some models do not have an interface and SCSI connector. For example, current personal computers are roughly classified into a desktop (desktop) type and a notebook type (also called a laptop type).

Generally, a desktop personal computer is designed with emphasis on functionality and expandability, so that it is heavy and requires a large installation space, so the space factor is not good. However, when expanding the function, It is equipped with an expansion slot to which a board (circuit board) equipped with a circuit having each function can be detachably mounted, and because the board can be replaced according to the purpose, it is extremely expandable.

Therefore, in the case of a desktop personal computer 30 not equipped with a SCSI interface, as shown in FIG. 10, a SCSI board 31 equipped with a SCSI interface and a connector is mounted in an expansion slot and connected to the CPU 32, and the SCSI is connected. An optical disk subsystem 35 having a built-in optical disk unit 34 and a SCSI connector is connected via a cable 33.

On the other hand, the notebook personal computer is designed to be small (or thin) and lightweight in consideration of portability, and thus has an excellent space factor, but one CPU bus connector for connecting peripheral devices. (Or two) are prepared, so the expandability is not good.

Therefore, as shown in FIG. 9, an expansion box 42 for SCSI is connected to a CPU bus connector of a notebook computer 40 via a CPU bus cable 41.
After the CPU bus signal and the SCSI signal are mutually converted by the converter 43 incorporated in the expansion box 42,
The SCSI connector of the expansion box 42 is connected to the SCSI of the optical disk subsystem 35 via the SCSI cable 44.
It was connected to the connector. Also, in general, the converter 43
The electric power required by the notebook computer 40 was supplied via the CPU bus cable 41.

[0008]

However, two subsystems, an expansion box and an optical disk device,
It is troublesome to connect two different cables with different standards to a notebook computer, which is a host machine, because the connectors are different and there is no risk of incorrect connection. Furthermore, 2
There is a problem that the cost increases because each subsystem is required.

Moreover, not only does the notebook type personal computer having an excellent space factor lose its features, but it is extremely inconvenient to carry, and it has a space factor smaller than that of a desktop type personal computer in order to handle two cables. It may also deteriorate.

Further, since the notebook type personal computer is often used independently of a commercial AC power source as is called a laptop type, it uses a dry battery or a small rechargeable storage battery as a power source. Therefore, the internal circuit of itself is designed to save power, but by supplying extra power to the expansion box and the terminator of the cable described later, the usable time after charging the dry battery or storage battery is greatly increased. There was also the problem of being shortened to.

The present invention has been made in view of the above points, and a first object thereof is to facilitate the use of the optical disk device and to minimize the reduction of the space factor at a low cost. The second purpose is to maintain the usable time of a battery without burdening the power supply of the host machine. Furthermore, the third purpose is to save the power of the terminator.

[0012]

In order to achieve the above object, the present invention provides an optical disk subsystem provided with a SCSI connector in an optical disk subsystem used by connecting to a host machine provided with a CPU bus connector,
CP by connecting to the SCSI connector of the optical disk unit
The conversion means for converting the U-bus signal and the SCSI signal to each other and the CPU bus connector for connecting the conversion means to the host machine via the cable are housed in one housing.

The above conversion means is used as an S
A means for operating by being supplied with power from the power supply terminal of the CSI connector may be used.

Further, the SCSI side terminal of the conversion means and the SCSI connector of the optical disk unit are arranged close to each other, and the cable connecting the SCSI side terminal and the SCSI connector at the shortest distance and the impedance of the cable are regulated. One SCSI terminator is provided.

Further, each impedance resistance value for each line constituting the SCSI terminator may be set higher than the cable impedance of the SCSI standard.

Alternatively, in the above optical disk subsystem, a SCSI connector and a CP are used as external connectors.
It has a U-bus connector.

[0017]

The optical disk subsystem configured as described above includes an optical disk unit having a SCSI connector,
Since the conversion means connected to the SCSI connector of the optical disk unit and the CPU bus connector for connecting the conversion means to the host machine via the cable are housed in one housing, the conventional expansion box is unnecessary. Since only one cable is required, the connection is very easy, the cost is low and the reduction of the space factor can be minimized.

Moreover, in addition to the need for an expansion box,
By supplying the electric power required by the converting means from the optical disk unit housed in the same housing, the usable time can be maintained if the power source is a battery, without imposing any burden on the power source of the host machine. I can. further,
By supplying the required power from the power supply terminal of the SCSI connector, the wiring and mutual attachment / detachment can be easily performed, so that the man-hours for assembly, inspection, repair, etc. can be reduced, and the cost can be further suppressed.

Further, by arranging the SCSI side terminal of the converting means and the optical disk unit close to each other,
Since the length of the cable connecting the two can be shortened, only one SCSI terminator is required at each end of a cable of normal length, and the required power of the terminator can be halved.

Furthermore, since the cable is short, S
Even if the impedance resistance values of the lines forming the CSI terminator are set higher than the cable impedance of the SCSI standard, there is no risk of the signal level dropping or the waveform being broken, so the power of the terminator can be saved.

Alternatively, as the external connector of the optical disk subsystem, a SCSI connector is provided in addition to the CPU bus connector, and the SCS is internally provided to the SCSI connector.
By connecting the I signal line, it is possible to expand the system by connecting another subsystem equipped with a SCSI connector serially with a SCSI cable at a slight cost increase. There is.

[0022]

FIG. 1 is a block diagram showing a configuration of a first embodiment of an optical disk subsystem according to the present invention and a connection relationship with a host machine, which corresponds to the conventional example shown in FIGS. 9 and 10. The connector not shown in the conventional example is also shown.

Notebook computer 1 which is a host machine
Includes a CPU bus connector 1c as an external connector, and the CPU bus connector 1c is internally connected to the CPU 2 and various circuits not shown by a CPU bus.

The optical disk subsystem 3 is an optical disk unit 4 for internal incorporation having a SCSI connector 4s.
And a converter 5 which is a conversion means similar to a normal SCSI interface, and a CPU bus connector 6 which is an external connector.

The optical disk unit 4 is connected to each SCSI terminal (not shown) of the converter 5 by a SCSI connector 4s via a short SCSI cable 7 of about several cm, and each CP (not shown) of the converter 5 is also connected.
The U bus terminal is connected to each terminal of the CPU bus connector 6.

FIG. 2 is an external perspective view showing an example of the internal structure of the optical disk subsystem 3 according to the first embodiment shown in FIG. 1 with the cover removed. The optical disk subsystem 3 shown in FIG. 2 includes an optical disk unit 4 and a power supply unit 10 which are respectively mounted on the main frame 24.
The converter 5 hidden in the shield plate 25, the CPU bus connector 6 whose rear surface is shown, and the cooling fan 26.
And a front panel 27 and a cover 28.

AC power supplied through an AC cord (not shown) is input to the power supply unit 10 and the fan 26 to rotate the fan 26, and at the same time, to supply power to the power supply unit 10.
Is converted into a drive DC 12V and a circuit DC 5V and output to the optical disk unit 4 or other necessary circuits.

The SCSI connectors 4s (not shown) provided on the back surface of the optical disk unit 4 are connected to the respective SCSI terminals of the converter 5 by a short cable 7 having a pair of SCSI connectors at one end.

As shown in FIG. 1, the optical disk subsystem 3 constructed as described above and housed in a single housing has the CPU bus connector 6 and the CPU bus connector 1c of the notebook computer 1 as shown in FIG. The space between them may be simply connected by one CPU bus cable 8. Compared with the conventional example in which an expansion box 42 and a SCSI cable 44 are required in addition to the optical disk subsystem 35 and the CPU bus cable 41 shown in FIG. The connection is very simple, the cost is low, and the space factor is almost the same as the system of the desktop personal computer 30 shown in FIG.

Further, since the commercially available optical disk unit for internal incorporation can be used as it is,
The cost is lower than modifying an optical disk device that is commercially available as an independent subsystem, and an expansion box and a cable are not required compared to the conventional system, so the overall cost can be significantly reduced.

FIG. 3 shows a SCSI based on the SCSI standard.
FIG. 3 is a plan view showing an arrangement of each terminal of the connector, and Table 1 shows names of data lines and signal lines connected to each terminal. The SCSI connector 4s shown in FIG. 3 is provided with 50 terminals, and the upper row is composed of terminals # 1 to 25 and the lower row is composed of terminals # 26 to 50 in order from the left.

[0032]

[Table 1]

As shown in Table 1, the terminals # 1 to # 25 in the upper stage are all GND (ground) terminals except the central OPEN terminal # 13 and the RESERVED terminals # 12 and 14 on both sides thereof. Is. The OPEN terminal is a non-connection terminal. There is no special provision for the RESERVED terminal,
The use is determined between the devices to be connected, and on the cable side, terminals of corresponding numbers are connected by lines.

The lower terminals # 26 to 50 are connected to the center TER.
MPWR (power) terminal # 38 and RESERV on both sides of it
GND terminals # 35, 3 by sandwiching the ED terminals # 37, 39
6, 40 and one # 42 are provided, and the terminals # 26 to 34 on the left side thereof are terminals for data DB0 to DB7 and DBP each consisting of 8 bits and parity, and the terminals # 41 and 43 to 50 on the right side are Each signal ATN and BSY, AC
This is a terminal for K and the like. Note that all data and signals have negative logic.

The DC 5V power required by the converter 5 must be supplied from either the host machine side or the optical disk subsystem side. FIG. 11 shows a conventional S
According to the same idea as the CSI board 31 or the expansion box 42, DC5V power is supplied from the notebook computer 1 which is the host machine to the TERMMPWR of the CPU bus cable 8a.
It is a block diagram which shows an example of the connection at the time of supplying via a (power supply) line.

With the connection shown in FIG. 11, not only the power for the converter 5 in the optical disk subsystem 13a, but also the CPU bus cables 8a and S will be described later.
Since the power of each terminator of the CSI cable 7 must also be supplied, and the terminator consumes a certain amount of power, the usable time of the battery that is the power source of the notebook computer 1 is considerably shortened, which is very inconvenient for practical use. There is a problem.

FIG. 5 is a block diagram showing an example of a connection that can be easily considered when the power of DC 5V of the converter 5 is supplied from the optical disk subsystem 3b side to solve the problem. That is, of the power of the drive DC 12V and the circuit DC 5V supplied to the optical disk unit 4 by the power supply unit 10 having AC100V as an input power supply,
A part of the electric power of the circuit DC 5V is directly supplied to the converter 5.

With the connection shown in FIG. 5, the converter 5
Since the power of each terminator is obtained from the power supply unit 10, the usable time of the battery of the notebook computer 1 is not deteriorated at all. However, it is necessary to provide a power line connecting the power supply unit 10 and the converter 5 when assembling the optical disk subsystem 3b, which requires extra man-hours when removing the converter 5 for inspection or repair.

FIG. 4 is a block diagram showing the configuration and internal connection of the second embodiment of the optical disk subsystem according to the present invention. The DC 5V power of the converter 5 is supplied to the optical disk unit 4 and the TERMPWR of the SCSI cable 7a.
(Electric power) line.

The SCSI connector 4s of the optical disk unit 4 is originally connected to the TERMMPWR terminal # 38 by the SCS.
Since the DC5V power line is connected according to the I standard, and the SCSI cable is provided with the TERMPWR line, the SCSI cable 7a is the same as the SCSI cable 7 of the first embodiment, and the SCSI cable 7a shown in FIG. In the four embodiments, nothing is added to the first embodiment shown in FIG.

Therefore, since the power line of the converter 5 is simply connected to the TERMMPWR line of the SCSI cable 7a, there is no cost increase. Moreover, assembly,
At the time of inspection and repair, the connector on the side of the SCSI cable 7a can be attached / detached to / from the SCSI connector 4s of the optical disk unit 4, so the same effect as the connection method shown in FIG. There is.

FIG. 12 is a block diagram and a circuit diagram showing an example of a terminator in a conventional SCSI cable. FIG. 12A is a block diagram showing the arrangement of two terminators 9a provided at both ends of the SCSI cable 7. FIG. 1B is a circuit diagram showing an example of the impedance block 19a for each line that constitutes the terminator 9a.

In the SCSI standard, assuming a cable length of 6 m as a reference, a terminator is provided at each end of the cable to set the impedance of each line of data and signal to 9 m.
Since each data and signal are in the negative logic while being in the range of 0Ω to 135Ω, it is defined that each line is pulled up in the + direction.

Therefore, as shown in FIG. 12A, the optical disc subsystem 13b is provided with terminators 9a on the optical disc unit 4 side and the converter 5 side, respectively, and each impedance block 19a of the terminator 9a is shown in FIG. As shown in B), 220
Ω and 330 Ω resistors are connected in series, and DC5V is divided and supplied to the line. Therefore, the impedance resistance value of each line is 132Ω, and it is pulled up by the divided voltage value of 3V.

However, at all times (when the signal is off), 9.1 m is applied to each impedance block 19a through the voltage divider.
The current of A flows, and there are 18 data lines and 9 signal lines in total, so one terminator 9
It consumes a current of 164 mA for a. When the signal is turned on, the line becomes 0 V and 22.7 mA flows, so the amount of increase in current is 13.6 mA.

Therefore, the signal is on or the data is "1".
Assuming that the number of lines that have become n is n, the current consumption of one terminator 9a is 164 mA plus n times 13.6 mA, and as shown in FIG. With two, the current consumption will double,
The consumed current cannot be ignored, and when the packages are collectively housed in the housing as shown in FIG. 2, heat generation due to the housing may be a problem.

When the length of the SCSI cable reaches 6 m, the signal level is lowered and the waveform is disturbed due to the mismatch unless the line impedance is within the allowable range by providing the terminators at both ends. When the length becomes as short as about several cm, even if only one terminator is provided on one side, the level is not lowered and the waveform is not disturbed. Also, even if there is some impedance mismatch, it will not be a problem unless it is significantly different.

FIG. 6 is a block diagram showing a third embodiment of the optical disk subsystem in which the terminator is provided on only one side for the above reason. In the optical disk subsystem 3c shown in FIG. 6, the terminator 9a is provided in the optical disk unit 4, but since the SCSI cable 7 is short, even if it is provided in the converter 5, its operation does not change.

Since the terminator 9a of the third embodiment is the same as the terminator 9a shown in FIG. 12A, by providing only one terminator 9a, the level is not lowered and the waveform is not disturbed. The current consumption can be cut in half. Also, heat generation is reduced accordingly.

FIG. 7 is a block diagram and a circuit diagram showing a fourth embodiment of the optical disk subsystem. The impedance resistance value of the line by the terminator of the third embodiment shown in FIG. Is set higher than the upper limit (135Ω).

Since the terminator 9b of the optical disk subsystem 3d shown in FIG. 7A is composed of an impedance block 19b composed of a 1 KΩ pull-up resistor as shown in FIG. 7B, The impedance resistance value of each line is 1 KΩ and is pulled up by DC5V. With the internal configuration as shown in FIG.
If the cable length is at most 10 cm or less, even with one terminator having an impedance resistance value of 1 KΩ, there will be no level drop or waveform distortion that hinders data or signal transmission.

The terminator 9b thus constructed is
The current is always zero (when the signal is off), and even if the signal is on and the line becomes 0 V, only 5 mA of current flows, so the total current consumption is only n times 5 mA.

Since it is impossible for all the lines to be turned on, it is assumed that the maximum value of n = 10 in practice, and the current consumption is 300 mA to 50 mA, which is 1 mA compared with the third embodiment shown in FIG. It becomes / 6, and if n = 5, it decreases to 1/9 or less. Needless to say, it is half that of the conventional example shown in FIG. Therefore, the current consumption is greatly reduced, and heat generation is not a problem.

FIG. 8 is a block diagram showing a fifth embodiment of the optical disk subsystem according to the present invention. The optical disk subsystem 3e shown in FIG. 8 is provided with a SCSI connector 16 as an external connector in addition to the CPU bus connector 6, and the SCSI connector 16 includes a SCSI connector 4s of the optical disk unit 4 and a converter 5.
A SCSI cable connecting to and is branched and connected on the way.

The optical disk subsystem 3e thus configured connects the CPU bus connector 6 of the two external connectors as the IN side connector to the host machine via the CPU bus cable, and the SCSI connector 16 at the OUT side. As a connector, it can be connected via a SCSI cable to a subsystem equipped with another SCSI connector.

By connecting the subsystem (A) serially through the optical disk subsystem 3e, the SCS
It is possible to use the optical disk subsystem and the subsystem (A) even in a host machine having only a CPU bus connector without an I connector. Further, the system can be arbitrarily expanded by serially connecting the other subsystems (B) and (C) to the subsystem (A).

In the fifth embodiment, since it is not known what subsystem is connected to the SCSI connector 16 through what length of SCSI cable, both the optical disk unit 4 and the converter 5 comply with the SCSI standard. For example, it is better to provide and place the terminator 9a including the impedance block 19a shown in FIG.

[0058]

As described above, the optical disk subsystem according to the present invention can facilitate the use of the optical disk device and can minimize the reduction of the space factor at a low cost. In addition, if the power source is a battery, the usable time can be maintained without imposing a burden on the power source of the host machine. Furthermore, the power of the terminator can be saved.

[Brief description of drawings]

FIG. 1 is a first optical disc subsystem according to the present invention.
It is a block diagram which shows the structure of an Example, and the connection relationship with a host machine.

FIG. 2 is an external perspective view showing an example of an internal configuration of the first embodiment shown in FIG.

FIG. 3 is a plan view showing an arrangement of terminals of a SCSI connector.

FIG. 4 is a block diagram showing the configuration and internal connections of a second embodiment of the optical disc subsystem.

FIG. 5 is a block diagram showing an example of internal connections that can be easily considered to solve the problems of the optical disk subsystem.

FIG. 6 is a block diagram showing a configuration of a third embodiment of an optical disc subsystem.

FIG. 7 is a block diagram showing a configuration of a fourth embodiment of an optical disc subsystem and an example of its terminator.

FIG. 8 is a block diagram showing the configuration and internal connections of a fifth embodiment of the optical disc subsystem.

FIG. 9 is a block diagram showing a conventional example of a system configuration in which a notebook computer is used as a host machine.

FIG. 10 is a block diagram showing a conventional example of a system configuration in which a desktop personal computer is used as a host machine.

FIG. 11 is a block diagram showing a conventional example of a connection for supplying electric power to a converter.

FIG. 12 is a block diagram showing a conventional example of a terminator for a SCSI cable.

[Explanation of symbols]

 1 note type personal computer (host machine) 1c (host machine) CPU bus connector 3, 3a, 3b ... 3e optical disk subsystem 4 optical disk unit 4s (optical disk unit) SCSI connector 5 converter (converting means) 6 CPU bus connector (external) Connector) 7, 7a, SCSI cable (cable) 9a, 9b Terminator (SCSI terminator) 10 Power supply unit 16 SCSI connector (external connector) 19a, 19b Impedance block

Claims (5)

[Claims] 1. An optical disk subsystem for use by connecting to a host machine having a CPU bus connector, and an optical disk unit having a SCSI connector, and a CPU connected to the SCSI connector of the optical disk unit.
It is characterized in that a conversion means for converting a bus signal and a SCSI signal to each other and a CPU bus connector for connecting the conversion means to the host machine via a cable are housed in one housing. Optical disc subsystem. 2. The optical disk subsystem according to claim 1, wherein the converting means is a means for operating by being supplied with power from a power supply terminal of a SCSI connector of the optical disk unit. 3. The optical disk subsystem according to claim 1 or 2, wherein the SCSI side terminal of the conversion means and the SCSI connector of the optical disk unit are arranged close to each other, and
An optical disk subsystem comprising: a cable connecting a CSI-side terminal and the SCSI connector at the shortest distance; and a SCSI terminator that regulates the impedance of the cable. 4. The optical disk subsystem according to claim 3, wherein each impedance resistance value for each line constituting the SCSI terminator is set higher than a cable impedance of SCSI standard. 5. The optical disk subsystem according to claim 1, wherein a SCSI connector and the CPU bus connector are provided together as an external connector.