JP2006323906A - Disk detecting unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk detecting unit which is reliable by using an optical sensor to find a disk. <P>SOLUTION: The detecting unit radiates light through a 1st sensing hole specified to locate in the area other than the disk loading area on a disk tray and the 2nd sensing hole specified to locate in the disk loading area, and receives the reflected light to detect its level. It sets up a discrimination level based on the 1st received light level the detection means detects through the 1st sensing hole when there is no disk and decides whether there is a disk or not by comparing the discrimination level with the 2nd received light level the detection means detects through the 2nd sensing hole. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disk detection device, and more particularly to a disk detection device with high reliability for detecting the presence or absence of a disk by an optical sensor.

  Among the disk detection devices that detect whether or not a disk is currently mounted on the disk tray of the disk playback device (hereinafter, the presence or absence of a disk) in a current disk playback device (for example, an optical disk playback device), There has been proposed a disk detection device that defines a detection hole and uses the detection hole to determine the presence or absence of a disk by an optical sensor. The optical sensor of this disk detection device has a light emitting part (light emitting element) and a light receiving part (light receiving element), and the characteristics change depending on the individual optical sensors due to variations in the composition and bonding of the material of the element. Variation occurs. Here, the light receiving level is the light irradiated from the optical sensor to the detection hole to determine the presence or absence of the disk, when the disk is mounted on the mounting portion (hereinafter, there is a disk), or When a disk is not mounted (hereinafter, there is no disk), it is reflected by other reflecting objects (for example, a top plate), and the reflected light is received by the optical sensor, so that the light intensity is converted into an electric power value. Value.

Therefore, in Patent Document 1 below, in the manufacturing process of the disk reproducing apparatus, the light receiving level L1 when there is a disk on the disk tray and the light receiving level L2 when there is no disk are measured by the disk detecting device (L1 and L2 in FIG. 6a). Then, a determination level JL (Expression 1) serving as a reference for determining the presence / absence of a disk is set from these received light levels (JL in FIG. 6a) and stored in the memory. When setting the judgment level, if the difference between the received light level when the disc is present and the received light level when there is no disc is smaller than the predetermined range, it is proposed to warn that the sensor is abnormal. An abnormal warning can replace a defective optical sensor during manufacturing.

  Whenever the user loads the disc with the disc playback device, the light receiving level is detected using the detection hole defined in the mounting portion, and compared with the judgment level JL stored in the memory at the time of manufacture. (FIG. 6a), the presence or absence of a disk is determined. If the light reception level L3 is higher than the determination level JL (L3a in FIG. 6a), it is determined that there is a disk. If the light reception level L3 is lower than the determination level JL (L3b in FIG. 6a), it is determined that there is no disk. .

  However, when the optical sensor of the disk detection device becomes dirty due to dust or the like, or when the light reception level L decreases due to deterioration over time, the light reception level L3 falls below the determination level JL even when there is a disk ( L3a in FIG. 6b), there is a problem of erroneously determining that there is no disk even though there is a disk. Furthermore, in a disc playback device that opens and closes the disc tray to which the optical sensor is attached, even if the disc is not mounted on the disc tray, a component that becomes a reflector between the disc tray and the top plate, The amount of reflected sensor light increases and the received light level increases (L3b in FIG. 6c). In such a case, the conventional disk detection device that sets the determination level at the time of manufacture has a problem of erroneously determining that there is a disk even though there is no disk.

JP 09-091857 A

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is to provide a disk detection apparatus with high reliability for detecting the presence or absence of a disk by an optical sensor.

  A disc detection apparatus according to a preferred embodiment of the present invention includes a disc tray in which a mounting portion for mounting a disc is defined, a first detection hole defined in a portion of the disc tray other than the mounting portion, and a mounting portion A second detection hole defined; a detection means for irradiating light to the first detection hole and the second detection hole; and receiving the reflected light to detect a received light level; and A determination level setting means for setting a determination level for determining the presence / absence of the disk based on a first light receiving level when there is no disk detected using the first detection hole; A disc presence / absence determination unit that determines the presence / absence of the disc by comparing the second light receiving level detected by the detection unit with the second detection hole; The light reception level is If more greater, it is determined that the disc is present, when the first light receiving level is more than the determination level, it is determined that the disc is not.

  The light receiving level (first light receiving level) when there is no disk using the first detection hole that is defined by the detecting means in the portion of the disc tray other than the loading portion, that is, the portion that is not loaded with the disc. And a determination level for determining the presence / absence of a disk is set based on the first light reception level. Then, the second detection hole defined in the mounting portion is used to detect the second light reception level when there is a disk or when there is no disk, and the determination level is compared with the second light reception level. To determine the presence of a disk. As a result, by detecting the first light receiving level through the first detection hole by the detection means, the determination level can be reset by the determination level setting means at any time, so it is necessary to set the determination level in the manufacturing process. No. In addition, even if the sensor gets dirty due to dirt or the received light level decreases due to deterioration over time, the judgment level can be reset and the judgment level can be reduced by the same amount as the received light level. It is possible to prevent erroneous determination that there is no disk even though there is a disk. Therefore, the presence / absence of a disk can be accurately determined.

  In a further preferred embodiment, determination level registration means for registering the determination level set by the determination level setting means in a determination level list, and determination for determining whether or not the determination level is registered in the determination level list Level judgment means, and when the judgment level judgment means judges that the judgment level is registered in the judgment level list, the detection means does not detect the first light reception level and the second level is detected. Only the received light level is detected.

  The determination level registration means registers the determination level in the determination level list. Further, before detecting the light reception level, it is determined whether or not the determination level is registered in the determination level list. When the determination level has already been registered in the determination level list, only the second light reception level is detected by the second detection hole without detecting the first light reception level by the first detection hole. Then, the presence / absence of the disc is determined by comparing the determination level already registered in the determination level with the second light receiving level. As a result, when the determination level is already set, it is possible to omit the process of detecting the first light receiving level with the first detection hole, setting the determination level, and registering it in the determination level list. Therefore, the presence / absence of a disk can be determined efficiently in a short time.

  In a further preferred embodiment, a disk presence / absence information registration means for registering the disk presence / absence information of the mounting unit in a disk presence / absence information list, and a disk for determining whether or not the disk presence / absence information is registered in the disk presence / absence information list A presence / absence information determination means, and when the disk presence / absence information determination means determines that the disk presence / absence information is registered in the disk presence / absence information list, the process for determining the presence / absence of a disk is not performed, If all the disk presence / absence information is not registered in the disk presence / absence information list, the determination level list is deleted.

  The disk presence / absence information registration means registers the disk presence / absence information of the mounting unit in the disk presence / absence information list. If the disk presence / absence information determination unit determines that the disk presence / absence information is registered in the disk presence / absence information list before detecting the light reception level, the process ends without executing the disk presence / absence detection process. As a result, it is possible to omit the presence / absence detection of the disk of the mounting unit in which the disk presence / absence information is registered. Therefore, the presence / absence of a disk can be determined efficiently in a short time. Further, when the disk presence / absence information determination unit determines that not all the disk presence / absence information is registered in the disk presence / absence information list, the determination level is deleted. As a result, when the disc tray is opened and closed and all the disc presence / absence information in the disc presence / absence information list is erased, the judgment level is deleted and the judgment level is not registered in the judgment level list by the judgment level judgment means. Is confirmed, and a new determination level can be set again by the disk presence / absence detection process. Therefore, the presence / absence of a disk can be accurately determined.

  In a further preferred embodiment, it further comprises disc tray movement determining means for determining whether or not the disc tray is moving, and when the disc tray movement determining means determines that the disc tray is moving, The determination level is deleted from the determination level list.

  Before detecting the light reception level, it is determined whether or not the disc tray is moving. When it is determined that the disc tray is moving, the determination level registered in the determination level list is deleted, the second light receiving level is detected by the second detection hole, and the determination level is newly set again. As a result, the environment around the first detection hole and the second detection hole changes due to the movement of the disc tray (that is, the reflector located between the disc tray and the top plate is not constant), and the light receiving level changes. Even in such a case, the determination level can be reset. Therefore, the presence / absence of a disk can be accurately determined.

  In a further preferred embodiment, the disc tray has a rotary table, the rotary table has the mounting portion, the first detection hole is defined in a part of the rotary table other than the mounting portion, and The first detection hole and the second detection hole are defined on concentric circles around the rotation axis of the rotary table.

  A first detection hole defined in a part of the rotary table other than the mounting part and a second detection hole defined in the mounting part are defined on a concentric circle centered on the rotation axis of the rotary table. As a result, in the carousel type disk changer in which the rotating table having the mounting portion for mounting the disk is rotated and the disk to be reproduced is replaced, it is not necessary to make the disk detecting device movable, and all the rotation table is rotated. The first light receiving level and the second light receiving level can be measured by the first detection hole and the second detection hole. Therefore, the presence / absence of a disk can be determined efficiently, and the number of parts can be reduced.

  In a more preferred embodiment, the determination level is a level obtained by adding a predetermined level to the first light receiving level or multiplying a predetermined coefficient.

  Even if the optical sensor has the same conditions, a difference (error) occurs in the received light level every time the received light level is detected. Accordingly, by adding a predetermined level to the first light receiving level in advance or multiplying by a predetermined coefficient, the determination level is set in consideration of the level corresponding to the error. As a result, since the second light receiving level when there is no disk is smaller than the determination level, it can be determined that there is no disk. Therefore, the presence / absence of a disk can be accurately determined. The same condition here refers to, for example, a condition for detecting the light reception level in each of the first detection hole and the second detection hole when there is no disk and the disk tray is opened and closed. Further, there is a case where dust or the like adheres to the optical sensor and the received light level does not decrease due to deterioration over time.

  According to the present invention, the determination level can be reset every time reproduction is instructed, so there is no need to set the determination level in the manufacturing process, and there is a variation in the light reception level of the optical sensor, dust, etc. There is no misjudgment caused by adhering and fouling or a change in received light level due to deterioration over time. Furthermore, even when the presence / absence of a disk is determined while the disk tray is moving, the presence / absence of a disk can be reliably determined.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking a carousel type disk changer as an example. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is incorporated.

  First, a disk detection apparatus according to an embodiment of the present invention will be described in more detail with reference to FIG. 1 and FIG.

  FIG. 1 is a block diagram showing a configuration of a disk detection apparatus 100 according to an embodiment of the present invention. FIG. 1 a is a cross-sectional view taken along the axis OA when the second detection hole 203 is positioned on the disk detection device 100 in FIG. FIG. 1B is a cross-sectional view taken along the axis OA when the rotary table 110b is rotated and the first detection hole 202 is positioned on the disk detection device 100 in FIG. FIG. 2 is a plan view of a main part of a disk reproducing device 200 including the disk detecting device 100 according to the embodiment of the present invention. The disc detection apparatus 100 has detection means, and the detection means irradiates the first detection hole 202 and the second detection hole 203 with light, and receives the reflected light to detect the light reception level L. In this embodiment, the detection means includes a reflective optical sensor 101 including a light emitting element 101a and a light receiving element 101b, a DC power source 102 for driving the light emitting element 101a, a bias power source 103 for supplying a bias voltage to the light receiving element, and a load. A resistor 104 and an output terminal 105 are provided.

  Further, the disk detection device 100 includes a determination level setting unit, a disk presence / absence determination unit, and a disk tray movement determination unit. The determination level setting means sets a determination level for determining the presence or absence of a disk. The disk presence / absence determining means determines the presence / absence of a disk. Further, the disc tray movement determining means determines whether or not the disc tray is moving. In this embodiment, the CPU 107 executes determination level setting, determination of presence / absence of a disk, and determination of whether a disk tray is moving.

  Further, the disk detection device 100 includes a determination level registration unit and a disk presence / absence information registration unit. The determination level registration unit registers the determination level set by the determination level setting unit in the determination level list. The disk presence / absence information registration means registers the disk presence / absence information of the mounting unit in the disk presence / absence information list. In this embodiment, the CPU 107 registers the determination level in the determination level list and the disk presence / absence information in the disk presence / absence information list. The determination level list and the disk presence / absence information list are stored in the memory 108 (for example, RAM, EPROM, etc.).

Table 1 below is a disk presence / absence information list stored in the memory 108.

  Disk presence / absence information is registered in the disk presence / absence information list. By referring to this disk presence / absence information list, the disk playback unit plays back the disk mounted on the mounting unit registered as having a disk. When the disc tray is opened, all the disc presence / absence information registered in the disc presence / absence information list is deleted. In this embodiment, the disk presence / absence information includes an identifier (for example, a number or a character string) of the mounting unit 201 and a disk 109 presence / absence information (for example, a flag).

Table 2 below is a determination level list stored in the memory.

  A determination level JL is registered in the determination level list. By comparing this determination level JL with the second light receiving level L2 detected by the disk detection device 100 through the second detection hole 203, it is determined whether or not the disk 109 is in the mounting portion 201. The determination level JL is a level obtained by adding a predetermined level K to the first light reception level L1 detected by the disk detection device 100 through the first detection hole 202. Further, instead of adding the predetermined level K, a predetermined coefficient H may be multiplied.

  Even if the optical sensor has the same conditions, a difference (error) occurs in the received light level every time the received light level is detected. As a level corresponding to the error, a level obtained by adding a predetermined level K to the first received light level in advance or multiplying by a predetermined coefficient H is set as a determination level. The predetermined level K or the predetermined coefficient K may be set as appropriate in accordance with the characteristics of the light emitting element and the light receiving element used in the optical sensor and the error that actually occurs. Therefore, since the second light receiving level when there is no disk is smaller than the determination level, it can be determined that there is no disk. The same condition here refers to, for example, a condition for detecting the light reception level in each of the first detection hole and the second detection hole when there is no disk and the disk tray is opened and closed. Further, there is a case where dust or the like adheres to the optical sensor and the received light level does not decrease due to deterioration over time.

  Furthermore, the disk detection device 100 includes an A / D converter 106 and a disk tray 110 for placing a disk 109 (for example, a CD or a DVD) at a position away from the reflective optical sensor 101 by a predetermined distance. .

  As shown in FIG. 2, the disk reproducing device 200 includes a disk detecting device 100, a disk tray 110 including a slide tray 110a and a rotary table 110b, and a disk reproducing unit 204. The disc detection device 100 is attached to the slide tray 110a. The disc tray 110 opens and closes when the slide tray 110a slides in the direction of the arrow in FIG. Further, the rotary table 110b has a plurality of mounting portions 201a to 201f arranged around the rotation shaft 205, and can be provided with a plurality of disks 109, and is rotated by a motor (not shown) around the rotation shaft 205. (In this embodiment, counterclockwise). By rotating the turntable 110b, it is possible to switch the disc to be played.

  In the rotary table 110b, a plurality of first detection holes 202a to 202f and a plurality of second detection holes 203a to 203f are detected in order to detect whether or not the disk 109 is arranged on the mounting portion 201 by the disk detection device 100. Is prescribed. The first detection hole 202 is defined in a part of the turntable 110b other than the mounting portion. Using the first detection hole 202, the optical sensor 101 detects the first light reception level L1. The second detection hole 203 is defined in the mounting portion 201. In this example, the second detection hole 203 uses the opening function defined in order to avoid contact between the disk reproducing unit 204 and the rotary table 110b. Using the second detection hole, the second light receiving level is detected by the optical sensor. Further, the first detection hole and the second detection hole are defined on a concentric circle with the rotation shaft 205 as the center. This is because there is no need to make the disk detection device 100 movable, and the first light receiving level L1 and the second light receiving level L1 and the second detection hole 203 are all set in the first detection holes 202 and the second detection holes 203 only by rotating the rotary table 110b. This is because the light reception level L2 can be measured.

  Next, the operation of the disk detection device 100 will be specifically described.

  The disk detection apparatus 100 irradiates sensor light from the reflective optical sensor 101, receives the reflected light reflected by the disk 109, and uses the light intensity of the reflected light as a power value (hereinafter referred to as a light receiving level L). To detect. Specifically, when a forward direct current is passed through the light emitting element 101a of the reflective optical sensor 101, sensor light is emitted from the light emitting element 101a. The light reception level when the first detection hole 202 is irradiated with sensor light is defined as a first light reception level L1, and the light reception level detected when the second detection hole 203 is irradiated with sensor light is defined as a second light reception level L2. Detect as.

  More specifically, the operation of the disk detection device 100 will be described. When the sensor light is applied to the second detection hole 203 defined in the mounting unit 201, if the mounting unit 201 has the disk 109, the sensor light is The light is reflected by the disk 109 and received by the light receiving element 101b as reflected light 111a having a high light intensity (FIG. 1a). When the mounting unit 201 does not have the disk 109, the sensor light passes through the second detection hole 203 and is reflected by other components (for example, the top plate 112), and is reflected by the light receiving element 101b as reflected light 111b having low light intensity. Received light. When the sensor light is irradiated to the first detection hole 202 defined in a part other than the mounting part 201 of the turntable 110b, the light receiving level is set to the second detection hole 203 without the disk 109 in the mounting part 201. As in the case of detection, the sensor light passes through the first detection hole 202 and is reflected by other components, and is received by the light receiving element as reflected light 111c having low light intensity (FIG. 1b). Here, the light intensity of the reflected light 111c is equivalent to that of the reflected light 111b and is weaker than that of the reflected light 111a.

  When the light receiving element 101b receives the reflected light 111, a photovoltaic force is generated in the light receiving element 101b. The magnitude of this photovoltaic power varies depending on the intensity of the reflected light 111 received. Then, based on the magnitude of the electromotive force generated in the light receiving element 101b, the output current I flows in the forward direction of the light receiving element, and a voltage drop occurs in the load resistor 104. This voltage drop is output from the output terminal 105 as the received light level L. Therefore, the light reception level L2 output when the light reception level is detected by the first detection hole 202 (that is, when the light receiving element 101b receives the reflected light 111c), the disk 109 is mounted by the second detection hole 203. This is equivalent to the light receiving level L1a that is output when the detection is performed in the absence of the part 201 (that is, when the light receiving element 101b receives the reflected light 111b), and the disk 109 is mounted by the second detection hole 203. The detection level is lower than the light reception level L1a output when the detection is performed in the state 201 (that is, when the light receiving element 101b receives the reflected light 111a). The light reception level L output from the output terminal 105 is converted from an analog signal to a digital signal by the A / D converter 106 and transmitted to the CPU 107.

  Next, the disk reproduction process will be described in detail with reference to FIGS.

  FIG. 3 is a flowchart showing the disk playback processing of the disk playback apparatus 200 including the disk detection apparatus 100. First, when a reproduction start instruction is given by the user (for example, when a reproduction button is pressed), a disk detection process is executed (S301). The disc detection process detects whether or not the disc 109 exists in the mounting unit 201 (for example, the mounting unit 201a) positioned on the disc playback unit 204 when the playback button is pressed, and the disc detection information list shows the disc in the disc presence / absence information list. Register presence / absence information. In addition, when playback is instructed by pressing a disk button that can be played back by designating which of the disks 109 mounted in the mounting units 201a to 201f, the specified mounting unit 201 is designated. It is detected whether or not there is a disk 109.

  Next, with reference to the disk presence / absence information of the mounting unit 201a registered in the disk presence / absence information list in step S301, it is determined whether the mounting unit 201a has the disk 109a (S302). Then, when the mounting unit 201a has the disk 109a (S302: YES), the disk 109a is reproduced (S303). When there is no disk 109a in the mounting unit 201a (S302: NO), the rotary table 110b is rotated counterclockwise, and the process returns to step S301 to determine whether or not the disk 109 is in the mounting unit 201b. That is, if there is a reproduction instruction, the presence / absence of the disk 109 in the mounting unit 201 is determined. If the disk 109 is present, the disk 109 is reproduced. The process of determining the presence or absence of is repeated. If there is no disk 109 in all the mounting units 201, the disk reproduction process is terminated.

  In addition, during playback of the disc, if the user gives an instruction to stop playback, the playback of the disc 109a is stopped. If the user has not instructed to stop playback (for example, when playback of the disc 109a is completed or the user When another disk 109 is instructed to be reproduced by the above-described operation), it is determined whether there is a disk in the adjacent mounting unit 201b counterclockwise or in the instructed mounting unit 201 (S301 and S302).

  Next, a disk detection process according to a preferred embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 4 is a flowchart showing disk detection processing in the disk detection apparatus 100. FIG. 5 is a diagram showing a comparison between the second light reception level and the determination level. When the reproduction is instructed, it is determined whether or not the disc tray opening / closing operation has been executed before the reproduction is instructed (S401). Specifically, the determination is made based on whether all the disk presence / absence information in the disk presence / absence information list has been deleted. This is because, in this embodiment, when the disk tray is opened and closed, all the disk presence / absence information in the disk presence / absence information list is erased. When it is determined that the disc tray has been opened and closed (S401: YES), the determination level JL is deleted from the determination level list (S403).

  If it is determined that the disc tray has not been opened / closed before playback is instructed (S401: NO), it is determined whether the disc tray is currently moving (S402). Specifically, the determination is made based on whether or not a voltage is applied to a motor that opens and closes the disk tray. If the disc tray is moving (S402: YES), the determination level JL is deleted from the determination level list (S403). If the disc tray is not moving (S402: NO), the disc presence / absence information of the mounting unit 201 of the disc 109 that is instructed to be reproduced (for example, the mounting unit 201a that is located on the disc reproducing unit 204 when the reproduction is instructed) Is registered in the disk presence / absence information list (S404). When the disk presence / absence information of the mounting unit 201a is not registered in the disk presence / absence information list (S404: NO), it is determined whether or not the determination level is registered in the determination level list (S405). When the disk presence / absence information of the mounting unit 201a is registered in the disk presence / absence information list (S404: YES), the disk detection process is terminated.

  Next, when the determination level JL is not registered in the determination level list in step S405 (S405: NO), the first light receiving level L1 is detected using the first detection hole 202a (S406). Specifically, by using the first detection hole 202a defined in the rotary table 110b other than the mounting portion, the light reception level L in the absence of the disk 109a by the disk detection device 100 is set as the first light reception level L1. To detect. Then, a determination level JL obtained by adding a predetermined level K to the first light reception level L1 detected in step S406 is registered in the determination level list (S407), and the second light reception level L2 is detected by the second detection hole 203. (S408). In step S405, when the determination level JL is registered in the determination level list (S405: YES), the second detection hole 203 is not executed without detecting the first light reception level L1 and setting the determination level JL. Is used to detect the second light receiving level L2 (S408). Specifically, using the second detection hole 203a defined in the mounting portion 201a, the disc detection device 100 detects the received light level L with or without the disc 109a as the first received light level L1. .

  Then, the second light reception level L2 is compared with the determination level JL registered in the determination level list to determine whether or not the disk 109a is present in the mounting unit 201a, and the disk presence / absence information 201a is included in the disk presence / absence information list. Is registered (S409). Specifically, as shown in FIG. 5a, when the second light receiving level L2 is higher than the determination level JL (L2a in FIG. 5a), the presence / absence of the disc is indicated by the presence / absence information of the disc 109a in the mounting portion 201a. When it is registered in the information list and the second light receiving level L2 is equal to or lower than the determination level JL (L2b in FIG. 5a), it is registered in the disk presence / absence information list as disk presence / absence information that there is no disk in the mounting portion 201a.

  Further, when the optical sensor 101 of the disk detection device is contaminated with dirt or the like, or the light reception level L is lowered due to deterioration with time (second light reception levels L2a and L2b and the first light reception level L1 in FIG. 5b). Even so, each time the disk detection process is executed, the determination level is the same as that of the light receiving bell by resetting a new determination level JL (the determination level JL in FIG. 5b) based on the first light receiving level L1. The amount will decrease. As a result, it is possible to prevent erroneous determination that there is no disk even though there is a disk. Therefore, the presence or absence of the disk 109 can be reliably determined.

  Further, when the disk reproduction process is executed while the disk tray 110 is moving, the disk 109 is mounted when the first detection hole 202 and the second detection hole 203 are positioned near other parts in the disk reproduction apparatus 200. Even when the sensor light is not present, the sensor light is reflected by other components, and the light reception level L is increased (the second light reception level L2b and the first light reception level L1 in FIG. 5c). Also at this time, each time the disc detection process is executed, a new determination level JL (determination level JL in FIG. 5c) is reset based on the first light reception level L1, so that the determination level JL is also the same as the light reception level. The amount gets bigger. As a result, it is possible to prevent erroneous determination that there is a disk even though there is no disk. Therefore, the presence / absence of the disk 109 can be reliably determined.

  As described above, the preferred embodiment of the disk detection device according to the present invention has been described, and the first means defined by the detection means in the part of the rotary table other than the mounting part, that is, the part not mounted with the disk. The detection level is used to detect the first light reception level when there is no disk, and the determination level for determining the presence / absence of the disk is set based on the first light reception level. Then, the second detection hole defined in the mounting portion is used to detect the second light reception level when there is a disk or when there is no disk, and the determination level is compared with the second light reception level. To determine the presence of a disk. As a result, by detecting the first light receiving level through the first detection hole by the detection means, the determination level can be reset by the determination level setting means at any time, so it is necessary to set the determination level in the manufacturing process. No. In addition, even if the sensor is contaminated with dirt or the like and the received light level decreases due to deterioration over time, the judgment level can be reduced by the same amount as the received light level, so there is no disk even though there is a disk. Can be prevented from being erroneously determined. Therefore, the presence / absence of a disk can be accurately determined.

  In the present embodiment, the determination level is registered in the determination level list by the determination level registration means. Further, before detecting the light reception level, it is determined whether or not the determination level is registered in the determination level list. When the determination level has already been registered in the determination level list, only the second light reception level is detected by the second detection hole without detecting the first light reception level by the first detection hole. Then, the presence / absence of the disc is determined by comparing the determination level already registered in the determination level with the second light receiving level. As a result, when the determination level is already set, it is possible to omit the process of detecting the first light receiving level with the first detection hole, setting the determination level, and registering it in the determination level list. Therefore, the presence / absence of a disk can be determined efficiently in a short time.

  Further, in the present embodiment, the disk presence / absence information registration unit registers the disk presence / absence information of the mounting unit in the disk presence / absence information list. If the disk presence / absence information determination unit determines that the disk presence / absence information is registered in the disk presence / absence information list before detecting the light reception level, the process ends without executing the disk presence / absence detection process. As a result, it is possible to omit the presence / absence detection of the disk of the mounting unit in which the disk presence / absence information is registered. Therefore, the presence / absence of a disk can be determined efficiently in a short time. Further, when the disk presence / absence information determination unit determines that not all the disk presence / absence information is registered in the disk presence / absence information list, the determination level is deleted. As a result, when the disc tray is opened and closed and all the disc presence / absence information in the disc presence / absence information list is erased, the judgment level is deleted and the judgment level is not registered in the judgment level list by the judgment level judgment means. Is confirmed, and a new determination level can be set again by the disk presence / absence detection process. Therefore, the presence / absence of a disk can be accurately determined.

  Furthermore, in this embodiment, it is determined whether or not the disc tray is moving before detecting the light reception level. When it is determined that the disc tray is moving, the determination level registered in the determination level list is deleted, the second light receiving level is detected by the second detection hole, and the determination level is newly set again. As a result, the environment around the first detection hole and the second detection hole changes due to the movement of the disc tray (that is, the reflector located between the disc tray and the top plate is not constant), and the light receiving level changes. Even in such a case, the determination level can be reset. Therefore, the presence / absence of a disk can be accurately determined.

  Further, in the present embodiment, the first detection hole defined in the part of the rotary table other than the mounting portion and the second detection hole defined in the mounting portion are concentrically centered on the rotation axis of the rotary table. Stipulate. As a result, in the carousel type disk changer in which the rotating table having the mounting portion for mounting the disk is rotated and the disk to be reproduced is replaced, it is not necessary to make the disk detecting device movable, and all the rotation table is rotated. The first light receiving level and the second light receiving level can be measured by the first detection hole and the second detection hole. Therefore, the presence / absence of a disk can be determined efficiently, and the number of parts can be reduced.

  Furthermore, in the present embodiment, the optical sensor adds a predetermined level to the first received light level in advance because a difference (error) occurs in the received light level every time the received light level is detected even under the same conditions. Or, by multiplying by a predetermined coefficient, the determination level is set in consideration of the level corresponding to the error. As a result, since the second light receiving level when there is no disk is smaller than the determination level, it can be determined that there is no disk. Therefore, the presence / absence of a disk can be accurately determined. The same condition here refers to, for example, a condition for detecting the light reception level in each of the first detection hole and the second detection hole when there is no disk and the disk tray is opened and closed. Further, there is a case where dust or the like adheres to the optical sensor and the received light level does not decrease due to deterioration over time.

  Moreover, in this Embodiment, although the 1st detection hole was prescribed | regulated between the mounting parts of the site | parts other than the mounting part of a rotary table, respectively, at least 1 should just be prescribed | regulated to a rotary table. Preferably, a first detection hole is defined between all the mounting portions. By defining the first detection holes in all the mounting portions, the second light receiving level can be detected and the judgment level can be quickly set by the closest first detection hole. It is possible to reduce the time taken to detect whether or not is placed.

  Furthermore, in the present embodiment, the second detection hole uses an opening defined in order to avoid contact between the disk reproducing unit and the rotary table, but like the first detection hole, In addition, a hole or the like for detecting the second light receiving level may be defined in the mounting portion separately from the opening. Also in this case, the first detection hole and the second detection hole are defined concentrically around the rotation axis of the rotary table.

  Furthermore, in this embodiment, every time the mounting unit detects the presence / absence of a disk, if there is a disk in the mounting unit, the disk is immediately played back. Playback may be started from That is, before detecting the light reception level, it is confirmed whether or not the disk presence / absence information of all the mounting units is registered in the disk presence / absence information list. If the disk presence / absence information of all the mounted units is not registered, the disk presence / absence detection process is executed in all the mounted units and the disk presence / absence information of all the mounted units is registered in the disk presence / absence information list. It is also possible to sequentially play back the disks in the mounting unit registered as being in the presence / absence information list.

  Further, in the present embodiment, whether or not the disk tray opening / closing operation has been executed is determined based on whether or not all the disk presence / absence information in the disk presence / absence information list has been erased. A switch or the like that can determine the open / close state of the disc tray may be provided, and it may be determined whether or not the disc tray open / close operation has been executed according to the state of the switch.

  Furthermore, in the present embodiment, the carousel type disk changer has been described as an example. However, the apparatus has a disk reproducing apparatus for reproducing by mounting only one disk, and a magazine for arranging and storing a plurality of disks in the apparatus. The disk detection apparatus of the present invention may be used in a disk changer apparatus that pulls out and plays back a disk stored in a magazine. For example, the disk detection device and the first detection hole and the second detection hole defined in the disk tray are defined on the direction axis for opening and closing the disk tray (or on the direction axis for pulling out the disk from the magazine). Then, when the disc tray is opened and closed (or when the disc is pulled out from the magazine), the first detection level and the second detection level are detected using the first detection hole and the second detection hole. .

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

  The disc detection device of the present invention can be used for a disc playback device for any application, but can be suitably used for a disc playback device capable of mounting a plurality of discs.

It is a block diagram which shows the structure of the disk detection apparatus which is preferable embodiment of this invention. It is a top view of the principal part of a disc reproducing | regenerating apparatus provided with the disc detection apparatus by preferable embodiment of this invention. It is a flowchart which shows the disk reproduction | regeneration processing of a disk reproduction apparatus provided with the disk detection apparatus which is preferable embodiment of this invention. It is a flowchart which shows the disk detection process of the disk detection apparatus which is preferable embodiment of this invention. It is a figure which shows the comparison with the 2nd light reception level which is preferable embodiment of this invention, and a determination level. It is a figure which shows operation | movement of the conventional disc detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Disc detection apparatus 101 Optical sensor 102 DC power supply 103 Bias power supply 104 Load resistance 105 Output terminal 106 A / D converter 107 CPU
108 Memory 109 Disc 110 Disc tray 110a Slide tray 110b Rotating table 111 Reflected light 112 Top plate 200 Disc reproducing device 201 Mounting portion 202 First detection hole 203 Second detection hole 204 Disc reproducing portion 205 Rotating shaft 206 Base portion I Output Current L1 First light reception level L2 Second light reception level JL Determination level

Claims (6)

A disc tray with a mounting section for mounting the disc,
A first detection hole defined in a portion of the disc tray other than the mounting portion;
A second detection hole defined in the mounting portion;
Detecting means for irradiating light to the first detection hole and the second detection hole and receiving the reflected light to detect a light reception level;
Determination level setting means for setting a determination level for determining the presence or absence of the disk based on a first light receiving level when the disk is not detected by the detection means using the first detection hole; ,
A disc presence / absence judging means for judging the presence / absence of the disc by comparing the judgment level with a second light receiving level detected by the detection means using the second detection hole;
The disc presence / absence judging means judges that the disc is present when the second light receiving level is higher than the judgment level, and when the second light receiving level is equal to or lower than the judgment level, Disc detection device that determines that there is no disk. Determination level registration means for registering the determination level set by the determination level setting means in a determination level list;
Judgment level judgment means for judging whether or not the judgment level is registered in the judgment level list;
If the determination level determination means determines that the determination level is registered in the determination level list, the detection means detects only the second light reception level without detecting the first light reception level; The disk detection apparatus according to claim 1. Disk presence / absence information registration means for registering the disk presence / absence information of the mounting unit in a disk presence / absence information list;
Disk presence / absence information determination means for determining whether or not the disk presence / absence information is registered in the disk presence / absence information list;
When the disk presence / absence information determination unit determines that the disk presence / absence information is registered in the disk presence / absence information list, the process for determining the presence / absence of a disk is not performed, and all the disk presence / absence information lists are included in the disk presence / absence information list. 3. The disk detection device according to claim 1, wherein the determination level list is erased when the information is not registered. A disc tray movement determining means for determining whether or not the disc tray is moving;
The disk detection device according to claim 1, wherein the determination level is deleted from the determination level list when the disk tray movement determination unit determines that the disk tray is moving. The disc tray has a rotary table;
The rotary table has a plurality of the mounting portions;
The first detection hole is defined in a part of the turntable other than the mounting portion;
5. The disk detection device according to claim 1, wherein the first detection hole and the second detection hole are defined on a concentric circle centered on a rotation axis of the rotary table.   6. The disk detection device according to claim 1, wherein the determination level is a level obtained by adding a predetermined level to the second light receiving level or multiplying a predetermined coefficient.

Images