Patent Application
20130217291
The present disclosure relates to a method for disassembling a plasma display device.
In recent years, as an image display device appropriate for slimming and upsizing, a plasma display device using a plasma display panel (hereinafter referred to as a PDP) has been mass-produced and rapidly diffused.
The PDP is mounted on a display section of the plasma display device. The PDP is configured by a front plate formed with a display electrode, a dielectric layer, a protective layer and the like on a glass substrate, and a rear plate formed with an address electrode, a barrier rib, a phosphor layer and the like on a glass substrate. The front plate and the rear plate are arranged as opposed to each other so as to form a minute discharge space between. both substrates, and peripheral edges of both substrates are sealed by fit glass. A discharge space is sealed. with a discharge gas formed by mixing inert gases such as a neon gas (Ne) and a xenon (Xe) gas.
A metal support plate as a chassis member is pasted to the rear surface of the rear plate of the PDP with an adhesive joint member such as a thermal conduction sheet interposed therebetween. The metal support plate has a function as the chassis member as well as a function as a heat sink. The chassis member is used. to be attached with a circuit board for driving the PDP, and the heat sink is used to efficiently dissipate heat generated by driving the PDP. Further, the plasma display device is mounted with a front frame and a back cover for protecting the PDP and the circuit board.
Incidentally, with the rapid diffusion of plasma display devices in recent years, the number of used and waste plasma display devices is on the rapid increase. Moreover, with increase in production amount of plasma display devices, the absolute number of defective PDP units in a manufacturing process is also on the increase. Accordingly, from viewpoints of environmental issues and resource savings, it is becoming important to develop and introduce a technique of disassembling the used and waste plasma display device or the defective PDP unit generated in the manufacturing process so as to recycle members or reproduce them as raw materials.
Disassembling the plasma display device into a recyclable form requires separation of the PDP, the metal support plate and the circuit board. Thereat, a variety of methods for separating the PDP unit have hitherto been proposed. For example, there has been proposed a method of heating the surface of a PDP by a hot plate to decrease bonding strength of a bonding member bonding the PDP and the metal support plate, so as to peel the PDP and the metal support plate from the bonding member (refer to PTL 1, for example).
For disassembling the plasma display device into a recyclable form, the plasma display device is collected to a disassembly plant. However, the number of disassembly plants for plasma display devices has hardly been changed with respect to the increase in number of disassembly processing on plasma display devices, and hence the number of disassembly processing per plant is on the increase. There has thus been a challenge to increase disassembly processing ability of the disassembly plant.
PTL1: Unexamined Japanese Patent Publication. No. 2005-116346
The present disclosure relates to a method for disassembling a plasma display device including a plasma display panel having a front plate and a rear plate, and a metal support plate bonded to the rear plate of the plasma display panel with a bonding member interposed therebetween. The method includes irradiating with infrared rays from a side of the front plate constituting the plasma display panel, to heat the bonding member between the plasma display panel and the metal support plate so as to decrease bonding strength, and thereafter to separate the plasma display panel and the metal support plate.
Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.
In
Next, a detailed structure of PDP unit 19 will be described using
Next, a method for disassembling plasma display device 10 will be described using
As shown in
Next, circuit board 15 is removed from metal support plate 14 of PDP unit 19 (S2).
Next, as for PDP unit 19, bonding member 16 is heated by infrared-ray irradiation to reduce bonding strength, thereby separating PDP 11 and metal support plate 14 (S3).
Then, front plate 20 and rear plate 21 constituting PDP 11 are separated (S4). Constituents such as an electrode and a dielectric formed in each of glass substrates constituting front plate 20 and rear plate 21 are removed, and thereafter, the glass substrates are subjected to dissolution treatment or the like, so as to be recycled as glass materials.
Next, a method at the time of separating DP 11 and metal support plate 14 will be described in detail. First, a heater (not shown) of infrared ray emitting section 31 is energized in a state where PDP unit 19 is placed on support 32 such that the side of front plate 20 of PDP 11 is opposed to infrared ray emitting section 31.
Infrared rays emitted from infrared ray emitting section 31 are transmitted through support 32, and PDP 11 is irradiated with the infrared rays. Front plate 20 of PDP 11 has a structure including a display electrode, a dielectric layer, a protective layer and the like on the glass substrate, but since about 85% thereof is transparent, most of the infrared rays, with which the irradiation was performed, are transmitted through front plate 20. Since the electrode, phosphor and the like are applied to all over rear plate 21, about 30% of the infrared rays, with which the irradiation was performed, is transmitted, but the rest thereof is all absorbed in rear plate 21. Due to this absorption, a temperature of rear plate 21 suddenly rises, and simultaneously, bonding member 16 tightly joined with rear plate 21 is also rapidly heated. This bonding member 16 is rapidly heated by direct heating by infrared rays and thermal conduction from rear plate 21.
As thus described, when bonding member 16 is rapidly heated to a temperature at which its bonding strength decreases, for example to a temperature of about 200 degrees, the bonding strength of bonding member 16 decreases, thereby allowing peeling of PDP 11 and metal support plate 14 in a short time.
Herein, for confirming the range of an effective peak wavelength in infrared heating, a peak wavelength of infrared rays used for heating was changed, to measure the time until the temperature of bonding member 16 reached 200 degrees. Table 1 shows this result.
As shown in Table 1, as the infrared ray peak wavelength is longer, the temperature of bonding member 16 reaches 200 degrees tends to be longer, and when the peak wavelength exceeds 3.0 μm, the time not shorter than 10 minutes is required. The shorter the time required for separating PDP 11 and metal support plate 14, the better it is, and considering a tact time in a disassembly plant, it is desirable to use infrared rays with its peak wavelength being in the range of the order of 1 μm to 3 μm.
Further, the distance between. infrared ray emitting section −and PDP 11 may be set such that an energy distribution of infrared rays, with which irradiation was performed, becomes uniform at the time of the infrared rays reaching front plate 20.
Moreover, although the disassembly method of placing PDP 11 on support 32 configured by glass or the like which transmits infrared rays and irradiating it with infrared rays from the lower side has been described in the present embodiment, another disassembly method may be applied. For example, a similar effect can be obtained when PDP 11 is arranged on support 32 such that infrared ray emitting section 31 and front plate 20 of PDP 11 are positioned in a mutually opposed manner and irradiation is performed with infrared rays in a state where PDP 11 and infrared ray emitting section 31 are erected (arrangement made by rotating the structure of
As thus described, according to the present embodiment, it is possible to easily separate PDP 11 and metal support plate 14 in a short time. It is thereby possible to efficiently disassemble used plasma display device 10 and defective plasma display device 10 generated in a manufacturing process step.
Further, since infrared heating is performed by thermal radiation, PDP 11 and infrared ray emitting section 31 may be placed with an arbitrary distance held therebetween, and front plate 20 constituting PDP 11 and infrared ray emitting section 31 are not necessarily brought into close contact with each other.
Moreover, to deal with upsizing of facilities, an area of infrared ray emitting section 31 may be increased by adding the number of infrared heaters, thereby facilitating upsizing of the device.
The present disclosure is useful in efficiently disassembling a used plasma display device and a defective plasma display device generated in a manufacturing process step.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-190299 | Sep 2011 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2012/002668 | Apr 2012 | US |
| Child | 13847128 | US |
