Patent Application
20220184735
The present disclosure relates to a laser marking method and a scanning optical apparatus. For example, the present disclosure relates to a scanning optical apparatus having a resin subjected to marking through use of a laser.
In recent years, as a method of managing components and units, there has been known a method of identifying and managing an object by irradiating the object with laser light to subject the object to marking (hereinafter referred to as “laser marking”). In a case in which the object of the laser marking is a resin molded product, when the resin molded product is irradiated with the laser light, the laser light is transmitted through a surface of the resin molded product to heat carbon black in a resin. The heated carbon black heats and melts the peripheral resin, locally decomposes the resin, and generates fine foam (hereinafter referred to as “foaming”) from the inside. Through the foaming, the resin on the surface of the resin molded product is pushed up from the inside, and in general, a whitish protruding portion raised by about 5 μm to about 50 μm is formed. The protruding portion becomes a whitish mark, and becomes visually recognizable (Japanese Patent Application Laid-Open No. H05-092657).
However, even with a resin molded product having a color close to white or a resin molded product having a dark color, the following difficulties occur depending on, for example, molding conditions. That is, in a case in which silver streaks being silver traces caused on the surface have occurred, even when the laser marking is performed, a sufficient contrast between the color of the marked portion and the peripheral color cannot be obtained, and the visibility is lowered.
In addition, a component that requires a highly accurate shape, for example, an optical box of a scanning optical apparatus, is molded by fine foam molding in order to improve dimensional stability. In this case, the fine foam molding is a molding method in which nitrogen or carbon dioxide in a supercritical state is added to a melted resin to form fine air bubbles each having a diameter of 100 μm or less inside a molded product. When the fine foam molding is performed, traces left after the air bubbles generated by the resin flowing in the mold are stretched on the surface of the molded product (hereinafter referred to as “swirl marks”) are caused on the molded product. The color of the surface of the molded product on which the swirl marks have been caused does not exhibit a sufficient contrast with respect to the color of the portion marked by the laser marking. There is also a concern in that, when a one-dimensional or two-dimensional bar code is marked under a state in which a sufficient contrast cannot be obtained by the laser marking, the bar code may fail to be stably read by a reader.
The present disclosure has been made under such circumstances, and has an objective to provide laser marking with satisfactory visibility irrespective of a surface state of a resin molded product.
In order to solve the above-mentioned disadvantage, according to the present disclosure, there is provided a laser marking method of performing marking by irradiating an object made of a resin with laser light, the laser marking method comprising: a first step of melting or carbonizing a first region of the object; and a second step of engraving a mark by irradiating a second region in the first region with the laser light.
According to the present disclosure, there is provided a scanning optical apparatus configured to form an electrostatic latent image by irradiating a photosensitive member with laser light, the scanning optical apparatus comprising: a casing of which at least one portion is formed of a resin; a first region which is melted or carbonized in the at least one portion formed of the resin; and a second region subjected to engraving processing in the first region.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, a laser marking method according to each of embodiments of the present disclosure and a scanning optical apparatus including a resin component subjected to marking by the laser marking method are described. In the following description, like components are denoted by like reference symbols.
In the following description, the laser marking apparatus (not shown) includes a laser irradiation device (not shown) configured to apply the laser light 2 and a controller (not shown) configured to control the laser irradiation device. The controller (not shown) of the laser marking apparatus (not shown) includes, for example, a CPU, a ROM, and a RAM, and controls a laser marking operation of the laser marking apparatus in accordance with a program stored in the ROM while using the RAM as a temporary work area. Accordingly, the controller (not shown) also controls, for example, an output (W) and a moving direction (scanning direction) of the laser irradiation device (not shown) when the laser light is applied therefrom. In regard to the movement of the laser light, the laser irradiation device may be configured to move, or the object may be configured to move.
With reference to
With reference to
Subsequently, with reference to
According to the first embodiment, the laser marking is performed within the region 13 obtained by melting the surface 11S of the resin 11 by the laser light 12. Thus, even when silver streaks or the like are caused on the surface 11S of the resin 11, the laser marking with satisfactory visibility can be stably provided without being affected by a surface state of a resin molded product.
With reference to
The optical box 29 is a resin molded product molded from a black resin. The optical box 29 is subjected to the laser marking through use of the laser marking method described with reference to
The semiconductor laser unit 21 being a light source, the anamorphic collimator lens 22, the light deflector 25, the fθ lens 27 being an imaging member, and the BD lens 31 are fixed to the optical box 29 by, for example, press-fitting, bonding, or screw-fastening. The semiconductor laser unit 21 emits the laser beam L. The anamorphic collimator lens 22 images, as a line image, the laser beam L emitted from the semiconductor laser unit 21 on a reflecting surface of the rotary polygon mirror 24. The rotary polygon mirror 24 is driven to rotate by the light deflector 25, to thereby deflect the laser beam L. Then, the laser beam deflected by the rotary polygon mirror 24 is transmitted through the fθ lens 27, to thereby be imaged and scanned on the scanned surface 28 (for example, the surface of a photosensitive drum being a photosensitive member).
In order to stably image the laser beam L on the scanned surface 28 of, for example, the photosensitive drum, it is required to maintain the positions and postures of the anamorphic collimator lens 22 and the fθ lens 27 with high accuracy. Accordingly, dimensional errors in the optical box 29 at portions relating to the positioning of optical elements including the anamorphic collimator lens 22 and the fθ lens 27 are required to be suppressed to or less than a range of from 10 μm to 30 μm.
For dimensional stability, fine foam molding is used for molding the optical box 29. When the fine foam molding is performed, swirl marks occur in a molded product. The swirl marks are traces left after air bubbles generated at the tip of a flowing resin are stretched on the surface of the molded product. Unless the object is an exterior component, the swirl marks are considered to exert no influences on performance, but when the laser marking is performed, the marked portion often fails to exhibit a sufficient contrast with respect to its periphery. Accordingly, as described with reference to
In addition, in order to reduce the influences of vibration strength and thermal expansion, a resin mixed with an inorganic reinforcing material including glass fiber, glass beads, mica, or carbon fiber is used as the material of the optical box 29. In this case as well, with related-art laser marking methods, a substance mixed into the surface of the molded product may be raised to cause a portion with a non-uniform color tone, and hence a sufficient contrast may not be obtained. To deal with this issue as well, as described with reference to
The one-dimensional barcode 36 includes at least one piece of information including, for example, a component number, a component molding date, a production lot, a stratification of a component manufacturer or a material, a serial number, and a production place. Meanwhile, the two-dimensional bar code 37 includes, for example, optical performance data measured by a step of assembling the scanning optical apparatus 100. When the scanning optical apparatus 100 images and scans the laser beam L, it is possible to improve the optical performance by performing, for example, electrical correction based on the above-mentioned information. The information included in the one-dimensional bar code 36 and the two-dimensional bar code 37 may be other information.
In this manner, the laser marking method according to the first embodiment is carried out on the optical box 29. Thus, even in an optical box using a resin subjected to fine foam molding or mixed with an inorganic reinforcing material, a one-dimensional bar code or a two-dimensional bar code that can be stably read by a reader can be laser-marked without being affected by a surface state of the resin. The first embodiment has been described by taking the one-dimensional bar code and the two-dimensional bar code as an example of indications relating to the unit (optical box 29) of the scanning optical apparatus 100, but a number, a character, or other information may be used. The mark includes a one-dimensional bar code, a two-dimensional bar code, a number, and a character, and serves to indicate information relating to the component on which the mark is formed.
Further, the type, wavelength, and output value of the laser light for the laser marking described as an example in the first embodiment are merely examples, and the present disclosure is not limited thereto.
Further, the optical box 29 is subjected to the marking in the first embodiment, but the same effect can be obtained when the marking is performed on a lid (not shown) of the optical box 29 or the semiconductor laser unit 21. That is, a place on which the laser marking method according to the first embodiment is performed may be any portion molded with a resin.
As described above, according to the first embodiment, the laser marking with satisfactory visibility can be provided irrespective of the surface state of the resin molded product.
With reference to
In the following description, it is assumed that an apparatus (not shown) including the heater includes a controller (not shown) configured to control the heater. It is assumed that the controller (not shown) of the apparatus (not shown) including the heater includes, for example, a CPU, a ROM, and a RAM, and controls the apparatus (not shown) including the heater in accordance with a program stored in the ROM while using the RAM as a temporary work area. Accordingly, the controller (not shown) also controls, for example, a temperature of the heater, a heating time, and movement of the heater.
With reference to
Subsequently, with reference to
As described above, according to the second embodiment, the laser marking with satisfactory visibility can be provided irrespective of the surface state of the resin molded product.
In the first embodiment and the second embodiment, high-power laser light and a heater are applied to create a region having a color close to black, and the marking is performed by whitening a resin with low-power laser light in the created region as illustrated in
In such a manner, the laser marking can be performed so that the mark becomes darker than the peripheral color. When an area of the mark 55 such as a two-dimensional bar code is large, it is possible to shorten a time period required for the laser marking by performing the laser marking in the third embodiment.
It is also to be understood that the laser marking methods according to the second embodiment and the third embodiment can be applied to the scanning optical apparatus as described in the first embodiment.
It is further to be understood that the present disclosure can be adapted not only to the scanning optical apparatus but also to a component or unit using a resin.
As described above, according to the third embodiment, the laser marking with satisfactory visibility can be provided irrespective of the surface state of the resin molded product.
In
The developing device 1030 develops the electrostatic latent image formed on the photosensitive drum 1010 with toner, to thereby form a toner image. The toner image formed on the photosensitive drum 1010 (on the image bearing member) is transferred, by a transfer device 1050, onto a sheet P serving as a recording material supplied from a cassette 1040, and the unfixed toner image transferred onto the sheet P is fixed by a fixing device 1060 to be delivered to a tray 1070. The photosensitive drum 1010, the charger 1020, the developing device 1030, and the transfer device 1050 constitute an image forming unit. The printer 1000 also includes a power supply apparatus 1080, and supplies electric power from the power supply apparatus 1080 to a controller 5000 and a driver, for example, a motor. The controller 5000 includes a CPU (not shown), and controls, for example, an image forming operation performed by the image forming unit and a conveying operation for the sheet P. The image forming apparatus to which the scanning optical apparatus 100 including the optical box 29 subjected to the marking by the laser marking method according to the present disclosure can be applied is not limited to the image forming apparatus having the configuration illustrated in
As described above, according to the fourth embodiment, the laser marking with satisfactory visibility can be provided irrespective of the surface state of the resin molded product.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2020-206265, filed Dec. 11, 2020, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-206265 | Dec 2020 | JP | national |
