JPS6079871A - Laser beam recorder - Google Patents

Abstract

PURPOSE:To improve the safety of the recorder by mounting a drum with an output of a means deiscriminating the presence of a photosensitive drum in a laser beam recorder possible for interrupting laser light. CONSTITUTION:A driving means of a momentary switch 10 is provided to the photosensitive drum or a cartridge. When the photosensitive drum is mounted, at least one of switches 10 is turned on. When the drum is not mounted or incompletely mounted, all the switches 10 are kept turned off. A decoder circuit 14 brings a signal A to H level when the switches 10 are all turned off and act to a laser drive circuit 12 and a control circuit 13 so as to inhibit generation of laser light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a laser beam recording device, and particularly to a laser beam recording device that can block laser light.

[Prior art] Laser beam printers use a drum or belt-shaped photoreceptor to scan a finely focused laser beam and use it as a light source, but when the photoreceptor I/ram is not installed in the device However, laser light is now being generated. Therefore, if laser light is generated at I5 where the photosensitive drum is not attached to the apparatus, the laser light will be reflected in a complicated manner inside the printer, and as a result, the laser light may leak out of the apparatus. Generally, the energy of this type of laser light is at a fairly low level, but due to the characteristics required of the printer, it is used in a very finely focused manner, so the energy density is at a fairly high level. Therefore, if the laser light leaking outside enters 11, there is a risk of causing damage to 1''.

For this reason, in consideration of safety, it is common practice to provide a cover that is tightly sealed to prevent laser light from leaking outside the printer. This is one of the reasons behind Blink's low price. Further, for operation or maintenance purposes, the main body cover may be opened and the apparatus may be operated with the photosensitive drum removed. For example, this corresponds to the case when dealing with a paper jam, etc. In such a case, if there is a -11 such as a laser beam being generated due to an operation error, the Qj will be required to tightly close the main body cover. There are risks that cannot be prevented by simply doing so.

[Objective 1-1] An object of the present invention is to eliminate the drawbacks of the conventional example and provide a highly safe laser beam recording device. A further object of the present invention is to provide a laser beam recording device that can block laser light not only when a recording medium such as a photosensitive drum is not mounted, but also when a recording medium such as a photosensitive drum is mounted unreliably. It's about making suggestions.

Another object of the present invention is to provide a beam recording device that has a simple configuration that increases the safety of the device and can provide various types of information on a recording medium.

[Embodiment] The general configuration of a laser beam printer to which the present invention is applied will be described with reference to FIG. 1. l is a laser unit that includes a laser and a laser drive circuit;
is a collimator lens that converts laser light into parallel light. A laser beam 3 modulated by an image signal and made into parallel light by a collimator lens 2 is scanned by a rotating polygon mirror 5 which is rotated by a high-speed rotation motor 4. The scanned laser beam is reflected by the anti-N4 mirror 6 and irradiated onto the photosensitive drum 7.

8 is an fO lens that corrects focal fluctuations. Around the photosensitive tram 7, a charging device, a developing device, a recording paper transfer device, a cleaning device, etc. necessary for electrophotography are arranged.
Since these are well known to those skilled in the art, they will be omitted.

The present invention is applied to this 4JLI laser beam printer, and an example of the present invention incorporated into the apparatus shown in FIG. 2 will be described in detail below with reference to a block diagram.

Reference numeral 10 denotes a momentary switch that is turned on or off when the photoreceptor drum 7 or a cartridge containing the photoreceptor drum is installed, and in this example, three switches are used. ing. and,
In this example, the description will be made assuming that all momentary switches are in the OFF state when the photosensitive drum 7 is not attached to the apparatus. 11 is a part of the controller of the water device; 12 is a laser drive circuit; 14 is a decoder circuit that generates a signal according to the state jE of the momentary switch 10; and 13 is a decoder circuit that generates a signal according to the state of the momentary switch 10 and other conditions inside the device, This is a control device that controls the drive circuit 12. Further, 15 is a pull-up resistor.

Next, the operation will be described. The momentary switch 10 driving means is provided at an optimal position on the photosensitive drum 7 or the cartridge containing the photosensitive drum, etc., for executing the operation of the momentary switch 10. This is usually a protrusion or depression located in a position compatible with a momentary switch.

Next, when the photosensitive drum is attached to the apparatus, at least one of the momentary switches 10 is turned on. Therefore, if the photoreceptor drum is not installed or is incompletely installed, all the momentary switches 10 remain in the OFF state. The decoder circuit 14 forces the signal A when all the momentary switches 10 are OFF.
is considered to be H level. When signal A is at H level, it acts on laser drive circuit 12 and control device 13 to prohibit laser light generation. Therefore, if the photosensitive drum is not installed or is incompletely installed, the generation of laser light will be forcibly prohibited.

To explain in more detail, consider the case where the photosensitive drum 7 is completely attached. The photosensitivity of a photosensitive drum generally varies slightly depending on its manufacturing conditions. Conventionally, only the photoreceptor drums that affect the sensitivity within a certain standard type were selected and used, and the others could not be used, but the laser light intensity of these photoreceptor drums that could not be used was also adjusted appropriately. It is known that it can be used upwards. Therefore, if the laser beam intensity can be adjusted to distinguish the sensitivity of the photoconductor drum and automatically correct it, it will be possible to use photoconductor drums that were previously unusable, and the yield rate of photoconductor drums will be greatly improved. It becomes possible to set the value to -1. By using the momentary switch 10, the sensitivity of this photosensitive drum can be detected. In the wooden embodiment, the intensity of the laser beam can be adjusted according to the sensitivity of the photosensitive drum, which is classified into seven levels in total, using three momentary switches 1. In Figure 2, signal B indicates a signal line that controls the laser light intensity. This control is performed as follows.

Control J'II device 13 by input of decoder circuit 14
(M'3) is determined, the control device 12 analyzes the content, and controls the laser drive circuit 12 according to item B of (1). Note that signals C and D are horizontal blank signals, and D is an image signal.

The present invention includes various aspects, and for example, IS RAM information input to the decoder circuit 14 may be coded and classified into a large number of pieces of information, or a signal from the decoder circuit 14 to the control device 13 may be coded. may be converted into By converting the information into a code I, it is possible to output various types of information to the device with a simple configuration. Furthermore, it is clear that the same effect can be obtained even if the decoder circuit 14 is removed and the tram information is input as is to the control device 13. Furthermore, it is clear that it is easy to display drum information using a signal using an LED or to issue an alarm.

It is also possible to display whether the drum is correctly mounted or not using an LED or the like.

Note that the drum information is not limited to the sensitivity of the photosensitive drum, and may be information indicating, for example, the dimensions of the drum or the color of the toner used.

[Effects] As described above, according to the present invention, it is possible to confirm that the tram is normally mounted by the output from the determining means for determining the presence or absence of the photoreceptor drum e11. Since the laser beam can be cut off when normal attachment cannot be confirmed, application of the present invention makes it possible to provide an extremely safe and inexpensive laser beam recording device.

In addition, according to the present invention, the discrimination stage can output drum information such as drum sensitivity correction information at the same time, so it is possible to control ON/OFF of the laser beam and drum sensitivity correction and drum information with a simple configuration. Display, etc. can be performed.

[Brief explanation of drawings]

It is an ivy diagram. Here, ■... Laser unit, 4... High speed rotation motor, 6... Rotating polygon mirror, 7... Photosensitive tram, 10
...It is a momentary switch.

Claims (2)

[Claims] (1) A laser characterized by comprising a discriminating means for discriminating the presence or absence of a recording medium, and a laser light control means for blocking a laser beam for performing optical recording on the recording medium according to the output from the discriminating means. Beam recording device. (2) The first aspect of the present invention is characterized in that the information on the "r++ different hand pitch recording medium can also be outputted."
Laser beam recording head described in section.