JPH0646342B2 - Optical pickup standby method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup waiting method for waiting an optical pickup at a predetermined position after access, and particularly to an optical pickup waiting method effective for shortening access time.

<Prior Art> There is an automobile navigation system that uses a CD-ROM that stores map data. Such an automobile navigation system stores a large amount of map data in a CD-ROM, and is provided with a display device, a position measuring device for measuring the current position of the vehicle, and the like, and the map data corresponding to the vehicle position is stored in the CD-ROM. The ROM is read out from the ROM, drawn on the display screen, and a location cursor indicating the current position of the vehicle is drawn on the map, and the cursor is moved on the map according to the movement of the vehicle.

<Problems to be Solved by the Invention> When a map is displayed by a conventional automobile navigation system, the CD-ROM access time associated with the movement of the optical pickup occupies most of the processing time required for the display. . In particular, the enlarged map is drawn more often than the reduced view or the reference view, so after accessing the reduced view or the reference view near the center of the CD-ROM, the next enlarged view on the outer circumference side is accessed. If the position of the optical pickup is left as it is, the amount of movement of the optical pickup increases, and there is a problem that extra time is required for access.

In view of the above, an object of the present invention is to provide an optical pickup standby method that can shorten the access time by setting the optical pickup standby position near the map data of the enlarged view that was last accessed.

<Means for Solving the Problem> In the present invention, the above-mentioned problem is a means for storing the vicinity of the map data of the last-enlarged map, and a CD-RO.
This is achieved by means of moving the optical pickup to a position near the map data when the M player is in a standby state and making the optical pickup stand by at this position.

<Operation> The vicinity of the map data of the finally accessed enlarged view is stored, and when the CD-ROM player enters the standby state, the optical pickup is moved to the vicinity of the map data, and the optical pickup is made to stand by at this position.

<Embodiment> FIG. 1 shows an automobile navigation system capable of realizing the present invention.
It is a block configuration diagram of a system.

In the figure, 1 is a CD-ROM player, 2 is a CD-ROM on which map data is recorded, 3 is an optical pickup, and RF amplifier 4 is provided by optically reading digital information recorded on CD-ROM 2. To the signal processing circuit 5 via.

The signal processing circuit 5 demodulates the EFM signal input from the RF amplifier 4, separates the map data and the subcode, performs error detection / correction processing on the map data, and also the subcode and the lead-in area of the CD-ROM 2. The information read from is input to the system controller 6. For the error detection / correction processing in the signal processing circuit 5, first, the CI
The RC error correction circuit 5a interleaves the two-stage Reed-Solomon code for correction code CIRC (Cross
s Interleaved Read-Solomon Code) (corresponding to the first error correction processing), and the processing result is output to the second error correction circuit 5b. In addition, C for music
In the case of D, the processing result is output as a digital audio signal, passed through a DA converter and the like, and then reproduced.

2nd error correction circuit (2'nd Error Correcti on Circu
The it) 5b is a CD-R that has high reliability with a bit error rate (error rate) of 10 ⁻¹² , similar to computer equipment.
It is provided for ensuring the OM and performs a decoding error check such as a missed error or an erroneous correction in the CIRC of the CIRC error correction circuit 5a.

The system controller 6 analyzes the Q-channel of the subcode similarly input together with the lead-in area information input from the signal processing circuit 5, and finally accesses the address near the map data of the enlarged map, for example, the enlarged map data The head or last address is stored in the memory 7.

Reference numeral 8 denotes a standby position control unit, which moves the optical pickup 3 to the vicinity of the map data of the enlarged view stored in the memory 7 when the CD-ROM player 1 completes the access and enters a standby state after a certain period of time. The optical pickup 3 is made to stand by at the position.

Reference numeral 9 is a servo circuit, and the optical pickup 3 is a CD-RO.
A tracking servo unit that follows the eccentricity of M2,
The focusing servo unit for focusing the light on the signal surface of the CD-ROM 2, the feed servo unit for driving the feed motor (threat motor) 10 to move the optical pickup 3 to a predetermined position, and the spindle motor 11 at a constant linear velocity. It has a rotating CLV servo unit.

Reference numeral 12 is a host computer that controls the automobile navigation system, 13 is an interface, and 14 is a sensor for position detection. The sensor 14 has a geomagnetic sensor for detecting an absolute azimuth, a vehicle speed sensor for detecting a traveling distance, and a forward / backward movement. There are transmission sensors for detecting, steering sensors for detecting azimuth, and the like. Reference numeral 15 is an operation unit provided with various command keys, and 16 is a display unit composed of a liquid crystal, a cathode ray tube or the like.

The operation of FIG. 1 will be described below with reference to FIG.
FIG. 2 is a schematic diagram showing a recording area of map data recorded on a CD-ROM.

In the figure, A is a table of contents area for disclosing the map data recorded on the CD-ROM 2, B is a reduced map area covering a wide area, and C is a reduced map area B, for example.
Standard map area that describes the / 4 area in more detail,
D is, for example, an enlarged map area in which a quarter of the reference map area C is described in more detail.

Of the map data recorded in each of the above map areas B to D, the map data in the enlarged map area D is most frequently used, and therefore the access frequency to the enlarged map data is the highest. This is because the current location of your vehicle is often confirmed using more detailed enlarged map data, and the reference map data and reduced map data that show a wider area are rarely accessed, such as when confirming the rough direction of travel and the destination. This is because it is not done. Therefore, reduced map area B and standard map area C
If the optical pickup 3 is made to stand by at the access position after accessing, the extra time for moving the optical pickup 3 to the enlarged map area D is required when the enlarged map area D is accessed next time.

Therefore, in the present invention, the head or the last address of the enlarged map area D last accessed in the memory 7 is stored, and when the CD-ROM player 1 enters the standby state, the standby position control unit 8 causes the servo circuit 9 and the servo circuit 9 to operate. The feed motor 10 is operated to move the optical pickup 3 near the address, and the optical pickup 3 is made to stand by at this position. As a result, the loss time in the access time to the enlarged map area D having the highest access frequency can be reduced, and the enlarged map can be displayed quickly.

FIG. 3 is a flow chart of processing of the present invention.

When a map index indicating the current position of the own vehicle is input by a key operation of the operation unit 15 or when a map index corresponding to the current position of the vehicle is obtained, the system controller 6 outputs an access command (step 101). ).

When the access command is output, map data in a predetermined map area is accessed based on the access command (step 102), and the read map is displayed on the display unit 16. Thereafter, or in parallel with the processing of step 102, it is determined whether or not the access is made in the enlarged map area D (step 103), and YES.
If so, the address of the access position is stored in the memory 7 (step 104), and the optical pickup 3 near the address is stored.
Is waited for (step 105), and the process ends.

On the other hand, if the determination in step 103 is NO, in other words, if the reduced map area B other than the enlarged map area D or the reference map area C is accessed, then it is checked whether or not the standby address is stored in the memory 7. If there is no waiting address (step 106), the optical pickup 3 is made to stand by in the vicinity of the reduced map area B or the reference map area C that has been accessed (step 10).
7) If there is a standby address, the optical pickup 3 is made to stand by near the standby address in the enlarged geographical map area D according to the processing of step 105.

<Advantages of the Invention> According to the present invention, the vicinity of the map data of the last-enlarged map that has been accessed is stored, and when the CD-ROM player enters the standby state, the optical pickup is moved to the vicinity of the map data. Since the optical pickup is configured to stand by at the position, it is possible to reduce the loss time in the access time to the enlarged map area D having the highest access frequency and display the enlarged map quickly.

[Brief description of drawings]

FIG. 1 shows an automobile navigation system that can realize the present invention.
FIG. 2 is a block diagram of a system, FIG. 2 is a schematic diagram showing a recording area of map data recorded on a CD-ROM, and FIG. 3 is a flow chart of processing of the present invention. 1 ... CD-ROM player, 2 ... CD-ROM, 3 ... Optical pickup, 5 ... Signal processing circuit, 6 ... System controller, 7 ... Memory, 8 ... Standby position control section, 9 ... Servo circuit, 10 ... Feed motor (thread motor).

Claims (1)

[Claims] 1. A method for waiting for an optical pickup of a navigation system for a vehicle, wherein reduced, reference, and enlarged map data recorded on a CD-ROM is accessed by an optical pickup, and the optical pickup is made to stand by at a predetermined position after the access. Storing the start or end address of the enlarged map data accessed to, move the optical pickup to the position indicated by the stored address when the CD-ROM player enters the standby state, and make the optical pickup stand by at this position. Optical pickup standby method featuring.