Conductive structure and electrochromic device

Abstract

The utility model discloses a kind of electrically conductive structure and electrochromic device, the electrically conductive structure includes insulating substrate layer and two electrodes, the two electrodes are side by side and interval arrangement on the same surface of the insulating substrate layer, wherein, the insulating substrate layer can be bent, so that the two electrodes are arranged in space upside down opposition. The electrochromic device uses the electrically conductive structure of the utility model, the insulating substrate layer after bending covers the side of the electrochromic device, and the two electrodes are the bus electrode of the electrochromic device. The utility model electrically conductive structure adopts the integrated design of insulating substrate layer and two electrodes, the electrically conductive structure can realize the quick, convenient arrangement of bus electrode on the basis of ensuring electrically conductive function, and effectively prevent water oxygen and PVB glue from eroding electrochromic device and bus electrode. Through multiple protection mechanism, the utility model can significantly improve the water oxygen barrier property and long-term reliability of device.

Description

Technical Field

[0001] This utility model belongs to the field of electrochromic technology, specifically relating to a conductive structure and an electrochromic device. Background Technology

[0002] Electrochromic devices, capable of reversibly controlling their transmittance to visible light and solar radiation under a low-voltage DC electric field, have become key components in fields such as building energy conservation, automotive smart sunroofs, and information displays. The core structure of an electrochromic device is a multilayer thin-film system consisting of a transparent conductive layer, an electrochromic material layer, an electrolyte layer, an ion storage layer, and another transparent conductive layer. The two transparent conductive layers are connected to the positive and negative terminals of an external power supply, respectively. Currently, the industry commonly uses copper foil or silver paste to print bus electrodes, which are then bonded to the surfaces of the transparent conductive layers on both sides of the device and led out to an external power supply via lateral leads. However, with the increasing demand for large-area, irregularly shaped, and ultra-thin electrochromic devices, the above-mentioned electrode arrangement methods have revealed the following problems: 1) In the fabrication of large-area, irregularly shaped devices, traditional copper foil bonding easily leads to an increase in the number of copper foil bends, resulting in uneven electrode thickness distribution; silver paste is prone to breakage and poor soldering during screen printing, leading to increased contact resistance and localized overheating; 2) Complex process and low yield: Existing double-layer electrode technology often requires pre-attaching the electrodes to a flexible printed circuit board (FPC) before transferring the entire assembly to the device electrode area. Inserting bus electrodes during operation is difficult, and the subsequent hot-pressing process requires high positional accuracy, making rework difficult; 3) PVB adhesive in the intermediate layer and water and oxygen in the environment easily penetrate into the device interior, corroding the bus electrodes and functional layers, leading to device performance degradation and shortened lifespan. Conventional packaging protection methods are only implemented after the bus electrode arrangement is completed, making it difficult to achieve sufficient protection for the device.

[0003] Therefore, how to achieve low-resistance, scalable bus electrode arrangement in electrochromic devices, while simultaneously improving the reliability of water and oxygen barrier, has become a key technological bottleneck that urgently needs to be overcome to promote its industrialization. Utility Model Content

[0004] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing a conductive structure and an electrochromic device. This conductive structure, while ensuring conductivity, enables rapid and convenient placement of the busbar electrodes and effectively prevents water, oxygen, and PVB adhesive from corroding the busbar electrodes of the electrochromic device. Through multiple protection mechanisms, this invention significantly improves the water and oxygen barrier performance and long-term reliability of the device.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problem is: a conductive structure, which includes an insulating substrate layer and two electrodes. The two electrodes are arranged side by side at intervals on the same surface of the insulating substrate layer. The insulating substrate layer can be bent so that the two electrodes are arranged vertically opposite each other in space.

[0006] Preferably, each electrode is fixed to the surface of the insulating substrate layer by an adhesive layer, which is a conductive or non-conductive adhesive, and the adhesive layers corresponding to two electrodes are spaced apart.

[0007] Preferably, the adhesive layer is a non-conductive adhesive, and the adhesive layers corresponding to the two electrodes are integrally formed and cover the entire surface of the insulating substrate layer.

[0008] Preferably, each electrode includes a metal strip and a conductive adhesive strip disposed on at least the side of the metal strip near the adhesive layer.

[0009] Preferably, the surface of the insulating substrate layer is provided with two first insulating strips arranged side by side at intervals, and the two electrodes are disposed between the two first insulating strips, with the two electrodes and the two first insulating strips arranged side by side at intervals.

[0010] Preferably, the surface of the insulating substrate layer is provided with a second insulating strip, which is disposed between the two electrodes. In a specific embodiment, the second insulating strip may cover or replace the portion of the adhesive layer located between the two electrodes. With the second insulating strip replacing the portion of the adhesive layer between the two electrodes, the insulating substrate layer is thinner at the second insulating strip and is more easily bent.

[0011] Preferably, the insulating substrate layer is a sealing layer or a barrier film, wherein the sealing layer is formed by coating and curing a liquid sealing material, and the barrier film is a pre-formed film.

[0012] Preferably, the sealing layer is selected from epoxy resin, silicone sealant (SiR), modified silane sealant (MS), and butyl rubber (BR), and the barrier film is selected from polyethylene terephthalate (PET), ethylene vinyl acetate (EVA), ionic polymer interlayer (SentryGlas Plus, i.e., SGP), thermoplastic polyurethane (TPU), polyethylene (PE), polypropylene (PP), polyethylene naphthalate (PEN), polyimide (PI), polyetherimide (PEI), polytetrafluoroethylene (PTFE), and flexible acrylic materials (such as acrylic PMMA). Depending on the application requirements, the insulating substrate layer can be a sealing layer to prevent water and oxygen from corroding the electrochromic device and electrodes; the insulating substrate layer can also be a barrier film to block some water and oxygen while avoiding the risk of leakage and short circuit.

[0013] Preferably, the length of each electrode is greater than the length of the insulating substrate layer, and both ends of each electrode extend to the outer side of the insulating substrate layer. When this conductive structure is subsequently applied to an electrochromic device, a combination of two electrode lengths is used: a conductive structure with an electrode length greater than the length of the insulating substrate layer and a conductive structure with an electrode length less than the length of the insulating substrate layer. This ensures that the electrodes are completely covered by the insulating substrate when they overlap at adjacent sides of the device.

[0014] An electrochromic device is disclosed, comprising the aforementioned conductive structure, wherein the bent insulating substrate layer covers the sides of the electrochromic device, and the two electrodes serve as the busbars of the electrochromic device. The conductive structure of this invention allows for the rapid and convenient arrangement of the busbars, effectively protecting them from corrosion by water, oxygen, PVB adhesive, etc., and preventing corrosion of the busbars and the membrane area.

[0015] Preferably, the electrochromic device includes a first substrate layer, a first conductive layer, an electrochromic film layer, a second conductive layer, and a second substrate layer stacked sequentially from top to bottom. The upper edge of the second conductive layer is provided with a plurality of first grooves at intervals, and the lower edge of the first conductive layer is provided with a plurality of second grooves at intervals. The first grooves and second grooves are overlapped along the edge of the electrochromic device. The two electrodes arranged opposite each other in the conductive structure are a first bus electrode and a second bus electrode, respectively. A portion of the first bus electrode is embedded in at least one first groove and electrically connected to the second conductive layer, and a portion of the second bus electrode is embedded in at least one second groove and electrically connected to the first conductive layer.

[0016] Preferably, a notch is provided between the adjacent first and second grooves. The upper and lower sides of the notch are covered by a first insulating layer and a second insulating layer, respectively. The two sides of the first insulating layer are respectively laid on the surfaces of the first base layer and the second conductive layer, and the two sides of the second insulating layer are respectively laid on the surfaces of the first conductive layer and the second base layer. The first and second insulating layers can be selected from one or more of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyetherimide (PEI), polytetrafluoroethylene (PTFE), and acrylic (PMMA).

[0017] Preferably, the insulating substrate layer covers the sides of the electrochromic device, thereby protecting the bus electrode while preventing water and oxygen from entering the device and preventing the color-changing effect of the device from being affected by the failure of the electrochromic film layer.

[0018] Preferably, when the surface of the insulating substrate layer is provided with the two first insulating strips, the upper first insulating strip covers the sides of the first substrate layer, the first conductive layer, and the electrochromic film layer, while the lower first insulating strip covers the sides of the electrochromic film layer, the second conductive layer, and the second substrate layer. The first insulating strips can further block water and oxygen from entering the device, thereby further optimizing the color-changing effect of the device.

[0019] Preferably, when the surface of the insulating substrate layer is provided with the second insulating strip, the second insulating strip alternately covers the sides of the first substrate layer, the first conductive layer, the second conductive layer, and the second substrate layer. In this configuration, the conductive structure, while achieving conductivity, can also provide multiple layers of protection for the device, resulting in better water and oxygen barrier effects.

[0020] Preferably, the first conductive layer and the second conductive layer are selected from one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), graphene, and PEDOT:PSS, respectively, and the first bus electrode and the second bus electrode are selected from one of copper foil, copper foil tape, FPC, platinum, gold, and silver, respectively.

[0021] As a further preferred embodiment, the first conductive layer and the second conductive layer are respectively selected from one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), graphene and PEDOT:PSS, and the first bus electrode and the second bus electrode are respectively selected from one of copper foil, copper foil tape, FPC, platinum, gold and silver.

[0022] Compared with existing technologies, this invention has the following advantages: The conductive structure of this invention adopts an integrated design of an insulating substrate layer and two electrodes. This conductive structure, while ensuring conductivity, enables rapid and convenient placement of the busbar electrodes and effectively prevents water, oxygen, and PVB adhesive from corroding the electrochromic device and the busbar electrodes. Through multiple protection mechanisms, this invention can significantly improve the water and oxygen barrier performance and long-term reliability of the device. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the conductive structure in Example 1; Figure 2 This is a cross-sectional view of the conductive structure in Example 2; Figure 3 This is a cross-sectional view of the conductive structure in Example 3; Figure 4 This is a cross-sectional view of the conductive structure in Example 4; Figure 5 This is a cross-sectional view of the conductive structure in Example 5; Figure 6 This is a cross-sectional view of the conductive structure in Example 6; Figure 7 A top view of a conductive structure in which the length of each electrode does not exceed the length of the insulating substrate layer. Figure 8 A top view of a conductive structure in which the length of each electrode is greater than the length of the insulating substrate layer. Figure 9 This is a top view of the electrochromic device in Example 7; Figure 10 Enlarged Figure 9 AA section diagram; Figure 11 Enlarged Figure 9 Middle BB section view; Figure 12 Enlarged Figure 9 C-section view; Figure 13 This is a top view of the electrochromic device in Example 8; Figure 14 Enlarged Figure 8 AA section diagram; Figure 15 Enlarged Figure 8 Middle BB section view; Figure 16 This is a top view of the electrochromic device in Example 9; Figure 17 Enlarged Figure 16 Sectional view of A1-A1; Figure 18 Enlarged Figure 16 Sectional view of A2-A2; Figure 19 Enlarged Figure 16 Middle BB section view; Figure 20 This is a top view of the electrochromic device in Example 10; Figure 21 Enlarged Figure 20 Sectional view of A1-A1; Figure 22 Enlarged Figure 20 Sectional view of A2-A2; Figure 23 Enlarged Figure 20 Middle BB section view; For clarity, the dimensions of different components in the drawing have been enlarged non-proportionally. The specific reference numerals in the figure are as follows: 1-Conductive structure, 11-Electrode, 12-Insulating substrate layer, 13-Adhesive layer, 14-Conductive strip, 15-First insulating strip, 16-Second insulating strip, 17-First bus electrode, 18-Second bus electrode, 2-First base layer, 3-First conductive layer, 31-Second groove, 4-Electrochromic film layer, 5-Second conductive layer, 51-First groove, 6-Second base layer, 7-Lead electrode, 8-Notch, 81-First insulating layer, 82-Second insulating layer. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Components or structures not limited in this invention employ conventional techniques in the art.

[0025] Example 1: A conductive structure, such as Figure 1 As shown, the conductive structure 1 includes an insulating substrate layer 12 and two electrodes 11. The two electrodes 11 are copper foils and are arranged side by side at intervals on the same surface of the insulating substrate layer 12. The insulating substrate layer 12 can be bent so that the two electrodes 11 are arranged vertically opposite each other in space.

[0026] Example 2: A conductive structure, such as Figure 2 As shown, the conductive structure 1 includes an insulating substrate layer 12 and two electrodes 11. The two electrodes 11 are arranged side-by-side on the same surface of the insulating substrate layer 12. Each electrode 11 is fixed to the surface of the insulating substrate layer 12 by an adhesive layer 13, which is a conductive adhesive. The adhesive layers 13 corresponding to the two electrodes 11 are spaced apart. The insulating substrate layer 12 can be bent so that the two electrodes 11 are arranged vertically opposite each other in space. Specifically, in embodiment 2, the two electrodes 11 are copper foils, and the conductive adhesive bonded to the surface of the copper foil is the adhesive layer 13.

[0027] Example 3: A conductive structure, such as Figure 3 As shown, the conductive structure 1 includes an insulating substrate layer 12 and two electrodes 11. The two electrodes 11 are copper foils. The two electrodes 11 are arranged side by side at intervals on the same surface of the insulating substrate layer 12. Each electrode 11 is fixed to the surface of the insulating substrate layer 12 by an adhesive layer 13. The adhesive layer 13 is a non-conductive adhesive. The adhesive layers 13 corresponding to the two electrodes 11 are integrally formed and cover the entire surface of the insulating substrate layer 12.

[0028] Example 4: A conductive structure, such as Figure 4As shown, the conductive structure 1 includes an insulating substrate layer 12 and two electrodes 11. The two electrodes 11 are arranged side by side at intervals on the same surface of the insulating substrate layer 12. Each electrode 11 is fixed to the surface of the insulating substrate layer 12 by a conductive adhesive strip 14 and an adhesive layer 13. The adhesive layer 13 is a non-conductive adhesive. Specifically, each electrode 11 includes a copper foil and a conductive adhesive strip 14 disposed on the side of the copper foil near the adhesive layer.

[0029] Example 5: A conductive structure, differing from Example 3 in that, as shown in Example 3... Figure 5 As shown, two first insulating strips 15 are arranged side by side at intervals on the surface of the insulating substrate layer 12, and two electrodes 11 are disposed between the two first insulating strips 15. The two electrodes 11 and the two first insulating strips 15 are arranged side by side at intervals.

[0030] Example 6: A conductive structure, differing from Example 5 in that, as Figure 6 As shown, a second insulating strip 16 is provided on the surface of the insulating substrate layer 12. The second insulating strip 16 is disposed between the two electrodes 11, and the second insulating strip 16 replaces the portion of the adhesive layer 13 located between the two electrodes 11.

[0031] In embodiments 1-6 above, the length of each electrode 11 may not exceed the length of the insulating substrate layer 12, such as... Figure 7 As shown; the length of each electrode 11 can also be greater than the length of the insulating substrate layer 12, and both ends of each electrode 11 extend to the outside of the insulating substrate layer 12, as shown. Figure 8 As shown. When this conductive structure is subsequently applied to an electrochromic device, a combination of two conductive structures with different electrode lengths is used, that is, a conductive structure with a length of electrode 11 greater than the length of the insulating substrate layer 12 is used. Figure 8 ) and a conductive structure in which the length of electrode 11 is less than the length of insulating substrate layer 12 ( Figure 7 This ensures that the electrodes are completely covered by the insulating substrate when they overlap at adjacent sides of the device.

[0032] Example 7: An electrochromic device, such as Figures 9-12As shown, the electrochromic device adopts the conductive structure 1 of Embodiment 3. The bent insulating substrate layer 12 covers the side of the electrochromic device. The two electrodes 11 are the bus electrodes of the electrochromic device. Specifically, the electrochromic device includes a first base layer 2, a first conductive layer 3, an electrochromic film layer 4, a second conductive layer 5, and a second base layer 6 stacked sequentially from top to bottom. The upper edge of the second conductive layer 5 is provided with a plurality of first grooves 51 at intervals, and the lower edge of the first conductive layer 3 is provided with a plurality of second grooves 31 at intervals. The first grooves 51 and the second grooves 31 are overlapped along the edge of the electrochromic device. The two electrodes 11 arranged vertically opposite each other in the conductive structure 1 are the first bus electrode 17 and the second bus electrode 18. The first bus electrode 17 and the second bus electrode 18 are electrically connected to an external power source via lead-out electrodes 7. A portion of the first bus electrode 17 is embedded in at least one first groove 51 and electrically connected to the second conductive layer 5. A portion of the second bus electrode 18 is embedded in at least one second groove 31 and electrically connected to the first conductive layer 3. A notch 8 is provided between the left and right adjacent first grooves 51 and second grooves 31. The upper and lower sides of the notch 8 are covered by a first insulating layer 81 and a second insulating layer 82, respectively. The two sides of the first insulating layer 81 are respectively laid on the surfaces of the first base layer 2 and the second conductive layer 5. The two sides of the second insulating layer 82 are respectively laid on the surfaces of the first conductive layer 3 and the second base layer 6.

[0033] Example 8: An electrochromic device, differing from Example 7 in that, as Figures 13-15 As shown, the insulating substrate layer 12 covers the side of the electrochromic device.

[0034] Example 9: An electrochromic device, differing from Example 8 in that, as Figures 16-19 As shown, the electrochromic device of Embodiment 9 adopts the conductive structure 1 of Embodiment 5. The first insulating strip 15 located in the first groove 51 (i.e., the first insulating strip 15 located at the upper position) covers the side of the first substrate layer 2, the first conductive layer 3 and the electrochromic film layer 4. The first insulating strip 15 located in the second groove 31 (i.e., the first insulating strip 15 located at the lower position) covers the side of the second substrate layer 6, the second conductive layer 5 and the electrochromic film layer 4. The first insulating strips 15 at other positions are laid on the first substrate layer 2 and the second substrate layer 6 and are respectively connected to the first insulating strips 15 provided in the areas of the first groove 51 and the second groove 31.

[0035] Example 10: An electrochromic device, differing from Example 9 in that, as Figures 20-23 As shown, the electrochromic device of Embodiment 10 adopts the conductive structure 1 of Embodiment 6, and the second insulating strip 16 alternately covers the sides of the first base layer 2, the first conductive layer 3, the second conductive layer 5, and the second base layer 6.

[0036] In the above embodiments, the insulating substrate layer 12 is a sealing layer or a barrier film. The sealing layer is formed by coating and curing a liquid sealing material, and the barrier film is a pre-formed film. The sealing layer is selected from epoxy resin, silicone sealant (SiR), modified silane sealant (MS), and butyl rubber (BR). The barrier film is selected from polyethylene terephthalate (PET), ethylene vinyl acetate (EVA), ionic polymer interlayer (SentryGlas Plus, i.e., SGP), thermoplastic polyurethane (TPU), polyethylene (PE), polypropylene (PP), polyethylene naphthalate (PEN), polyimide (PI), polyetherimide (PEI), polytetrafluoroethylene (PTFE), and flexible acrylic materials (such as acrylic PMMA). The first insulating strip 15 and the second insulating strip 16 are made of the same material as the insulating substrate layer 12. The first conductive layer 3 and the second conductive layer 5 are respectively selected from one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), graphene, and PEDOT:PSS. The first bus electrode 17 and the second bus electrode 18 are respectively selected from one of copper foil, copper foil tape, FPC, platinum, gold, and silver. The first insulating layer 81 and the second insulating layer 82 are selected from one or more of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyetherimide (PEI), polytetrafluoroethylene (PTFE), and acrylic (PMMA).

Claims

1. A conductive structure, characterized in that, The conductive structure includes an insulating substrate layer and two electrodes, which are disposed side by side at intervals on the same surface of the insulating substrate layer. The insulating substrate layer can be bent so that the two electrodes are arranged vertically opposite each other in space.

2. The conductive structure according to claim 1, characterized in that, Each electrode is fixed to the surface of the insulating substrate layer by an adhesive layer, which is either conductive or non-conductive adhesive, and the adhesive layers for two electrodes are spaced apart.

3. The conductive structure according to claim 2, characterized in that, The adhesive layer is a non-conductive adhesive, and the adhesive layers corresponding to the two electrodes are integrally formed and cover the entire surface of the insulating substrate layer.

4. The conductive structure according to claim 3, characterized in that, Each of the electrodes includes a metal strip and a conductive adhesive strip disposed on at least the side of the metal strip near the adhesive layer.

5. A conductive structure according to claim 2, 3, or 4, characterized in that, The surface of the insulating substrate layer has two first insulating strips arranged side by side at intervals, and the two electrodes are disposed between the two first insulating strips. The two electrodes and the two first insulating strips are arranged side by side at intervals.

6. The conductive structure according to claim 5, characterized in that, The surface of the insulating substrate layer is provided with a second insulating strip, which is disposed between the two electrodes.

7. The conductive structure according to claim 1, characterized in that, The insulating substrate layer is a sealing layer or a barrier film. The sealing layer is formed by coating and curing a liquid sealing material, and the barrier film is a pre-formed film.

8. The conductive structure according to claim 7, characterized in that, The sealing layer is selected from one of epoxy resin, silicone sealant, modified silane adhesive and butyl rubber, and the barrier film is selected from one of polyethylene terephthalate, ethylene vinyl acetate, ionic polymer interlayer, thermoplastic polyurethane, polyethylene, polypropylene, polyethylene naphthalate, polyimide polyetherimide, polytetrafluoroethylene and flexible acrylate materials.

9. A conductive structure according to claim 1, characterized in that, The length of each electrode is greater than the length of the insulating substrate layer, and both ends of each electrode extend to the outside of the insulating substrate layer.

10. An electrochromic device, characterized in that, The electrochromic device employs the conductive structure described in any one of claims 1-9, wherein the bent insulating substrate layer covers the side of the electrochromic device, and the two electrodes are the bus electrodes of the electrochromic device.

11. The electrochromic device according to claim 10, characterized in that, The electrochromic device includes a first substrate layer, a first conductive layer, an electrochromic film layer, a second conductive layer, and a second substrate layer stacked sequentially from top to bottom. The upper edge of the second conductive layer is provided with a plurality of first grooves at intervals, and the lower edge of the first conductive layer is provided with a plurality of second grooves at intervals. The first grooves and second grooves are overlapped along the edge of the electrochromic device. The two electrodes arranged opposite each other in the conductive structure are a first bus electrode and a second bus electrode, respectively. A portion of the first bus electrode is embedded in at least one first groove and electrically connected to the second conductive layer, and a portion of the second bus electrode is embedded in at least one second groove and electrically connected to the first conductive layer.

12. The electrochromic device according to claim 11, characterized in that, A notch is provided between the first and second adjacent grooves on the left and right sides. The upper and lower sides of the notch are covered by a first insulating layer and a second insulating layer, respectively. The two sides of the first insulating layer are respectively laid on the surfaces of the first base layer and the second conductive layer, and the two sides of the second insulating layer are respectively laid on the surfaces of the first conductive layer and the second base layer.

13. The electrochromic device according to claim 11, characterized in that, The insulating substrate layer covers the sides of the electrochromic device.

14. The electrochromic device according to claim 11, characterized in that, When the surface of the insulating substrate layer is provided with the two first insulating strips, the upper first insulating strip covers the sides of the first base layer, the first conductive layer and the electrochromic film layer, and the lower first insulating strip covers the sides of the electrochromic film layer, the second conductive layer and the second base layer.

15. The electrochromic device according to claim 14, characterized in that, When the surface of the insulating substrate layer is provided with the second insulating strip, the second insulating strip alternately covers the sides of the first base layer, the first conductive layer, the second conductive layer, and the second base layer.

16. An electrochromic device according to any one of claims 11-15, characterized in that, The first conductive layer and the second conductive layer are respectively selected from one of indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, indium zinc oxide, graphene and PEDOT:PSS, and the first bus electrode and the second bus electrode are respectively selected from one of copper foil, copper foil tape, FPC, platinum, gold and silver.

Images